Separate supplied cohort rate and mix changes

{
  "label": "Supplied agency data"
}

{
  "code": "\nfunction fail(reason){throw new Error('input: '+reason);}\nfunction check(schema,value,where){\n if(value===null){if(schema.type==='null'||Array.isArray(schema.type)&&schema.type.includes('null'))return;fail(where+' wrong_type');}\n const type=Array.isArray(schema.type)?schema.type[0]:schema.type;\n if(type==='object'){\n  if(!value||typeof value!=='object'||Array.isArray(value))fail(where+' wrong_type');\n  for(const name of Object.keys(value))if(!Object.hasOwn(schema.properties,name))fail(where+' unknown_field');\n  for(const name of schema.required)if(!Object.hasOwn(value,name))fail(where+' missing_field');\n  for(const [name,shape]of Object.entries(schema.properties))check(shape,value[name],where+'.'+name);\n }else if(type==='array'){\n  if(!Array.isArray(value)||value.length>schema.maxItems)fail(where+' array_bound');\n  for(const item of value)check(schema.items,item,where+'[]');\n }else if(type==='string'){if(typeof value!=='string'||value.length>schema.maxLength)fail(where+' string_bound');}\n else if(type==='integer'){if(!Number.isSafeInteger(value)||value<schema.minimum||value>schema.maximum)fail(where+' integer_bound');}\n else if(type==='boolean'){if(typeof value!=='boolean')fail(where+' wrong_type');}\n else fail(where+' unsupported_type');\n}\nfunction id(value){if(typeof value!=='string'||!value||value.trim()!==value)fail('noncanonical_identity');return value;}\nfunction unique(values,reason){if(new Set(values).size!==values.length)fail(reason);}\nfunction safeAdd(a,b){if(a>Number.MAX_SAFE_INTEGER-b)fail('unsafe_sum');return a+b;}\nfunction day(value){if(!/^\\d{4}-\\d{2}-\\d{2}$/.test(value))fail('invalid_calendar_day');const ms=Date.parse(value+'T00:00:00Z');if(!Number.isFinite(ms)||new Date(ms).toISOString().slice(0,10)!==value)fail('invalid_calendar_day');return ms;}\nfunction refKey(ref){id(ref.assetId);if(ref.version<1)fail('positive_version_required');return JSON.stringify([ref.assetId,ref.version]);}\nfunction refValue(key){const pair=JSON.parse(key);return {assetId:pair[0],version:pair[1]};}\nfunction sortedRefs(keys){return [...keys].sort().map(refValue);}\n\nfunction lexIds(a,b){for(let i=0;i<Math.min(a.length,b.length);i++){if(a[i]<b[i])return -1;if(a[i]>b[i])return 1;}return a.length-b.length;}\nfunction maxSubset(rows,idField,feasible){let best=-1,ids=[],ties=0;for(let mask=0;mask<2**rows.length;mask++){const chosen=rows.filter((_,i)=>mask&(1<<i));if(!feasible(chosen))continue;const value=chosen.reduce((n,r)=>n+r.valuePoints,0),current=chosen.map(r=>r[idField]).sort();if(value>best){best=value;ids=current;ties=1;}else if(value===best){ties++;if(lexIds(current,ids)<0)ids=current;}}return {ids,value:best,ties};}\nfunction rat(n,d){if(d===0n)fail('zero_denominator');if(d<0n){n=-n;d=-d;}let a=n<0n?-n:n,b=d;while(b){const next=a%b;a=b;b=next;}return [n/a,d/a];}\nfunction ratAdd(a,b){return rat(a[0]*b[1]+b[0]*a[1],a[1]*b[1]);}\nfunction ratSub(a,b){return rat(a[0]*b[1]-b[0]*a[1],a[1]*b[1]);}\nfunction ratMul(a,b){return rat(a[0]*b[0],a[1]*b[1]);}\nfunction ratText(a){return a[0].toString()+'/'+a[1].toString();}\n\n\ncheck({\"type\":\"object\",\"properties\":{\"scopeId\":{\"type\":\"string\",\"maxLength\":128},\"selectionComplete\":{\"type\":[\"boolean\",\"null\"]},\"segments\":{\"type\":\"array\",\"items\":{\"type\":\"object\",\"properties\":{\"segmentId\":{\"type\":\"string\",\"maxLength\":128},\"beforeSuccesses\":{\"type\":[\"integer\",\"null\"],\"minimum\":0,\"maximum\":1000000},\"beforeTrials\":{\"type\":[\"integer\",\"null\"],\"minimum\":0,\"maximum\":1000000},\"afterSuccesses\":{\"type\":[\"integer\",\"null\"],\"minimum\":0,\"maximum\":1000000},\"afterTrials\":{\"type\":[\"integer\",\"null\"],\"minimum\":0,\"maximum\":1000000}},\"required\":[\"segmentId\",\"beforeSuccesses\",\"beforeTrials\",\"afterSuccesses\",\"afterTrials\"],\"additionalProperties\":false},\"maxItems\":20}},\"required\":[\"scopeId\",\"selectionComplete\",\"segments\"],\"additionalProperties\":false},context.input,\"input\");\nconst result=(function mixture(x){\n id(x.scopeId);unique(x.segments.map(s=>id(s.segmentId)),'duplicate_segment_id');\n for(const s of x.segments)for(const period of ['before','after'])if(s[period+'Successes']!==null&&s[period+'Trials']!==null&&s[period+'Successes']>s[period+'Trials'])fail('success_exceeds_trials');\n const unknown=x.segments.filter(s=>[s.beforeSuccesses,s.beforeTrials,s.afterSuccesses,s.afterTrials].includes(null)||s.beforeTrials===0||s.afterTrials===0).map(s=>s.segmentId).sort(),base={beforeRate:null,afterRate:null,rateChange:null,mixChange:null,totalChange:null,aggregateDirection:null,allSegmentDirection:null,directionReversal:null,unknownSegmentIds:unknown};\n if(!x.segments.length)return {status:'empty_supplied_segments',...base};\n if(x.selectionComplete!==true||unknown.length)return {status:'unknown',...base};\n const nb=BigInt(x.segments.reduce((n,s)=>n+s.beforeTrials,0)),na=BigInt(x.segments.reduce((n,s)=>n+s.afterTrials,0)),sb=BigInt(x.segments.reduce((n,s)=>n+s.beforeSuccesses,0)),sa=BigInt(x.segments.reduce((n,s)=>n+s.afterSuccesses,0)),before=rat(sb,nb),after=rat(sa,na);let rate=rat(0n,1n),mix=rat(0n,1n);const signs=[];\n for(const s of x.segments){const rb=rat(BigInt(s.beforeSuccesses),BigInt(s.beforeTrials)),ra=rat(BigInt(s.afterSuccesses),BigInt(s.afterTrials)),wb=rat(BigInt(s.beforeTrials),nb),wa=rat(BigInt(s.afterTrials),na),delta=ratSub(ra,rb);signs.push(delta[0]>0n?'improved':delta[0]<0n?'declined':'stable');rate=ratAdd(rate,ratMul(ratMul(ratAdd(wa,wb),rat(1n,2n)),delta));mix=ratAdd(mix,ratMul(ratMul(ratAdd(ra,rb),rat(1n,2n)),ratSub(wa,wb)));}\n const total=ratSub(after,before),aggregate=total[0]>0n?'improved':total[0]<0n?'declined':'stable',all=signs.every(s=>s===signs[0])?signs[0]:'mixed',reversal=(all==='improved'&&aggregate==='declined')||(all==='declined'&&aggregate==='improved');\n return {status:'decomposition_within_supplied_segments',...base,beforeRate:ratText(before),afterRate:ratText(after),rateChange:ratText(rate),mixChange:ratText(mix),totalChange:ratText(total),aggregateDirection:aggregate,allSegmentDirection:all,directionReversal:reversal};\n})(context.input);\ncheck({\"type\":\"object\",\"properties\":{\"status\":{\"type\":\"string\",\"maxLength\":128},\"beforeRate\":{\"type\":[\"string\",\"null\"],\"maxLength\":256},\"afterRate\":{\"type\":[\"string\",\"null\"],\"maxLength\":256},\"rateChange\":{\"type\":[\"string\",\"null\"],\"maxLength\":256},\"mixChange\":{\"type\":[\"string\",\"null\"],\"maxLength\":256},\"totalChange\":{\"type\":[\"string\",\"null\"],\"maxLength\":256},\"aggregateDirection\":{\"type\":[\"string\",\"null\"],\"maxLength\":128},\"allSegmentDirection\":{\"type\":[\"string\",\"null\"],\"maxLength\":128},\"directionReversal\":{\"type\":[\"boolean\",\"null\"]},\"unknownSegmentIds\":{\"type\":\"array\",\"items\":{\"type\":\"string\",\"maxLength\":128},\"maxItems\":100}},\"required\":[\"status\",\"beforeRate\",\"afterRate\",\"rateChange\",\"mixChange\",\"totalChange\",\"aggregateDirection\",\"allSegmentDirection\",\"directionReversal\",\"unknownSegmentIds\"],\"additionalProperties\":false},result,\"output\");\nreturn result;",
  "label": "Separate supplied cohort rate and mix changes",
  "memoryLimit": 16,
  "outputVar": "result",
  "timeout": 1000
}