Shadow pricing not working as it used to for the ctramp method #944

Open
Open
Shadow pricing not working as it used to for the ctramp method#944
Labels
BugSomething isn't working/bug f

Description

@i-am-sijia
i-am-sijia
opened on May 19, 2025

Describe the bug

In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.

A bit of background first. You can skip to the Issue section below if you prefer

Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.

In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.

As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.

Issue

However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.

I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.

To Reproduce
Steps to reproduce the behavior:

  1. Go to '...'
  2. Click on '....'
  3. Scroll down to '....'
  4. See error

Expected behavior
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
Add any other context about the problem here.

Activity

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    , 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
     blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

    Skip to content
    Shadow pricing not working as it used to for the ctramp method #944
    Open
    Open
    Shadow pricing not working as it used to for the ctramp method#944
    Labels
    BugSomething isn't working/bug f
    Description
    @i-am-sijia
    i-am-sijia
    opened on May 19, 2025
    Describe the bug
    In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
    A bit of background first. You can skip to the Issue section below if you prefer
    Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
    In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
    As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
    Issue
    However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
    I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
    To Reproduce
    
Steps to reproduce the behavior:
    1. Go to '...'
    2. Click on '....'
    3. Scroll down to '....'
    4. See error
    Expected behavior
    
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
    Screenshots
    
If applicable, add screenshots to help explain your problem.
    Additional context
    
Add any other context about the problem here.
    Activity
    Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
    Metadata
    Metadata
    Assignees
    No one assigned
      Labels
      BugSomething isn't working/bug f
      Type
      No type
      Projects
      • Phase 11
        Status
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      Milestone
      No milestone
      Relationships
      None yet
      Development
      No branches or pull requests
      Issue actions
      
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

      Skip to content
      Shadow pricing not working as it used to for the ctramp method #944
      Open
      Open
      Shadow pricing not working as it used to for the ctramp method#944
      Labels
      BugSomething isn't working/bug f
      Description
      @i-am-sijia
      i-am-sijia
      opened on May 19, 2025
      Describe the bug
      In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
      A bit of background first. You can skip to the Issue section below if you prefer
      Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
      In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
      As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
      Issue
      However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
      I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
      To Reproduce
      
Steps to reproduce the behavior:
      1. Go to '...'
      2. Click on '....'
      3. Scroll down to '....'
      4. See error
      Expected behavior
      
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
      Screenshots
      
If applicable, add screenshots to help explain your problem.
      Additional context
      
Add any other context about the problem here.
      Activity
      Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
      Metadata
      Metadata
      Assignees
      No one assigned
        Labels
        BugSomething isn't working/bug f
        Type
        No type
        Projects
        • Phase 11
          Status
          No status
        Milestone
        No milestone
        Relationships
        None yet
        Development
        No branches or pull requests
        Issue actions
        
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

        Skip to content
        Shadow pricing not working as it used to for the ctramp method #944
        Open
        Open
        Shadow pricing not working as it used to for the ctramp method#944
        Labels
        BugSomething isn't working/bug f
        Description
        @i-am-sijia
        i-am-sijia
        opened on May 19, 2025
        Describe the bug
        In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
        A bit of background first. You can skip to the Issue section below if you prefer
        Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
        In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
        As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
        Issue
        However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
        I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
        To Reproduce
        
Steps to reproduce the behavior:
        1. Go to '...'
        2. Click on '....'
        3. Scroll down to '....'
        4. See error
        Expected behavior
        
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
        Screenshots
        
If applicable, add screenshots to help explain your problem.
        Additional context
        
Add any other context about the problem here.
        Activity
        Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
        Metadata
        Metadata
        Assignees
        No one assigned
          Labels
          BugSomething isn't working/bug f
          Type
          No type
          Projects
          • Phase 11
            Status
            No status
          Milestone
          No milestone
          Relationships
          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

          Skip to content
          Shadow pricing not working as it used to for the ctramp method #944
          Open
          Open
          Shadow pricing not working as it used to for the ctramp method#944
          Labels
          BugSomething isn't working/bug f
          Description
          @i-am-sijia
          i-am-sijia
          opened on May 19, 2025
          Describe the bug
          In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
          A bit of background first. You can skip to the Issue section below if you prefer
          Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
          In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
          As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
          Issue
          However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
          I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
          To Reproduce
          
Steps to reproduce the behavior:
          1. Go to '...'
          2. Click on '....'
          3. Scroll down to '....'
          4. See error
          Expected behavior
          
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
          Screenshots
          
If applicable, add screenshots to help explain your problem.
          Additional context
          
Add any other context about the problem here.
          Activity
          Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            BugSomething isn't working/bug f
            Type
            No type
            Projects
            • Phase 11
              Status
              No status
            Milestone
            No milestone
            Relationships
            None yet
            Development
            No branches or pull requests
            Issue actions
            
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

            Skip to content
            Shadow pricing not working as it used to for the ctramp method #944
            Open
            Open
            Shadow pricing not working as it used to for the ctramp method#944
            Labels
            BugSomething isn't working/bug f
            Description
            @i-am-sijia
            i-am-sijia
            opened on May 19, 2025
            Describe the bug
            In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
            A bit of background first. You can skip to the Issue section below if you prefer
            Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
            In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
            As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
            Issue
            However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
            I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
            To Reproduce
            
Steps to reproduce the behavior:
            1. Go to '...'
            2. Click on '....'
            3. Scroll down to '....'
            4. See error
            Expected behavior
            
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
            Screenshots
            
If applicable, add screenshots to help explain your problem.
            Additional context
            
Add any other context about the problem here.
            Activity
            Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
            Metadata
            Metadata
            Assignees
            No one assigned
              Labels
              BugSomething isn't working/bug f
              Type
              No type
              Projects
              • Phase 11
                Status
                No status
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              Shadow pricing not working as it used to for the ctramp method #944
              Open
              Open
              Shadow pricing not working as it used to for the ctramp method#944
              Labels
              BugSomething isn't working/bug f
              Description
              @i-am-sijia
              i-am-sijia
              opened on May 19, 2025
              Describe the bug
              In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
              A bit of background first. You can skip to the Issue section below if you prefer
              Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
              In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
              As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
              Issue
              However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
              I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
              To Reproduce
              
Steps to reproduce the behavior:
              1. Go to '...'
              2. Click on '....'
              3. Scroll down to '....'
              4. See error
              Expected behavior
              
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
              Screenshots
              
If applicable, add screenshots to help explain your problem.
              Additional context
              
Add any other context about the problem here.
              Activity
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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                Shadow pricing not working as it used to for the ctramp method #944
                Open
                Open
                Shadow pricing not working as it used to for the ctramp method#944
                Labels
                BugSomething isn't working/bug f
                Description
                @i-am-sijia
                i-am-sijia
                opened on May 19, 2025
                Describe the bug
                In ActivitySim, work and school location choices are doubly constrained. Shadow prices are constants applied to destination zones to constrain the model, so that work and school location choice models do not assign more workers or students to any zone than the available opportunities in that zone.
                A bit of background first. You can skip to the Issue section below if you prefer
                Prior to v1.2, ActivitySim's shadow prices could be calculated using the ctramp method. Work and school location choice models are typically applied by segments, e.g., income segments for work, school grade segments for school. Instead of employments, destination choice size terms are calculated as targets by segment by zone. Shadow prices are then derived using these size terms along with the modeled workers (students) by segment by zone. When running shadow pricing, the size terms are also scaled to the sample population, ensuring that the destination choice results from a sample population run closely resemble those from a full population run. This is particularly useful when performing tasks such as calibration or global iterations with a sample population.
                In Phase 7, a new shadow pricing method, simulation was added to ActivitySim. Instead of comparing the modeled workers to the size terms by segment by zone, the simulation method compares the modeled workers directly to the total employment by zone to ensure the final workers match total jobs. The simulation method saves run time compared to the other two methods because it only re-simulates workers and zones that are over assigned in the previous iteration.
                As of release v1.3.4, users can choose their desired shadow pricing method among daysim, ctramp, and simulation. If a model was implemented using the ctramp method, a non-trivial effort would be required to switch to the simulation method, and vice-versa. Currently, there are still regions using the ctramp method.
                Issue
                However, in PR #635, shadow pricing is changed to be disabled when running a sample population under the ctramp method. This change has caused issues in some regions' ActivitySim implementation when not running the full population. Model results do not make sense (because no shadow pricing is applied) unless running the full population.
                I don't recall whether this change was discussed, apologies if I missed it. If it was, could someone please document the rationale? If the change was made for because of something with disaggregate accessibility, it would be good to know.
                To Reproduce
                
Steps to reproduce the behavior:
                1. Go to '...'
                2. Click on '....'
                3. Scroll down to '....'
                4. See error
                Expected behavior
                
Shadow pricing performs as it used to for ctramp method, to ensure backward compatibility.
                Screenshots
                
If applicable, add screenshots to help explain your problem.
                Additional context
                
Add any other context about the problem here.
                Activity
                Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
                Metadata
                Metadata
                Assignees
                No one assigned
                  Labels
                  BugSomething isn't working/bug f
                  Type
                  No type
                  Projects
                  • Phase 11
                    Status
                    No status
                  Milestone
                  No milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions