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finite_bands [2010/08/18 23:16]
jipsen
finite_bands [2010/08/20 16:26] (current)
jipsen
Line 1: Line 1:
=====Finite nonisomorphic bands===== =====Finite nonisomorphic bands=====
<html> <html>
-<style> +<div id="insert"></div> 
-td {padding-left:3px;padding-right:3px;} +<script src="http://math.chapman.edu/~jipsen/structures/ua.js"></script
-th {background-color:#f0f0f0;font-weight:normal;padding-left:3px;padding-right:3px;} +<script>init("Band",5,{idempotent:true,associative:true})</script>
-table {border-collapse:collapse;line-height:80%;}  +
-</style> +
-Format as <select id="format" onchange="displayAlgebras(filtlist)"> +
-<option value="table" selected>Table</option> +
-<option value="html">HTML</option> +
-<option value="text">Text</option>  +
-</select> +
-&nbsp; | &nbsp; Filter by +
-<b>Is subdirectly irreducible</b><input type="checkbox" name="si" id="siyes" onclick="document.getElementById('sino').checked=false;update()">yes  +
-<input type="checkbox" name="si" id="sino" onclick="document.getElementById('siyes').checked=false;update()">no &nbsp;  +
-<b>Is simple</b><input type="checkbox" name="simple" id="simpleyes" onclick="document.getElementById('simpleno').checked=false;update()">yes  +
-<input type="checkbox" name="simple" id="simpleno" onclick="document.getElementById('simpleyes').checked=false;update()">no &nbsp; | &nbsp; +
-Find algebras of size <input type="text" id="minsize" size="1" maxlength="2" value="1"> to <input type="text" id="maxsize" size="1" maxlength="2" value="5"><input type="button" value="Search" onclick="searchAlgebras()"> &nbsp; | &nbsp; Counts: <span id="counts"></span> +
- +
-<div id="algebras"></div> +
- +
-<script+
-function algebraToString(a,k,n) { +
- if (format=="html"){ +
-  var st="<div style=\"display:inline-block;border: 1px darkgray solid;\"><sup>"+n+"</sup>"+"<b>"+classname.slice(0,1)+"</b><sub>"+a.length+","+k+"</sub><br>"; +
-  for (var i=0; i<a.length; i++) { +
-    for (var j=0; j<a.length; j++) st = st+a[i][j]+(j==a.length-1?"":" &nbsp; "); +
-    st = st+"<br>"; +
-  } +
-  st = st+"</div> &nbsp;"; +
- }else if (format=="table"){ +
-  var st="<table style=\"display:inline-block;border: 1px darkgray solid;\"><tr><td colspan=\""+(a.length+1)+"\"><sup>"+n+"</sup>"+"<b>"+classname.slice(0,1)+"</b><sub>"+a.length+","+k+"</sub></td>;</tr><tr><th>&middot</th>"+
-  for (var i=0; i<a.length; i++) st += "<th>"+i+"</th>"; +
-  st += "</tr>"; +
-  for (var i=0; i<a.length; i++) { +
-    st += "<tr><th>"+i+"</th>"; +
-    for (var j=0; j<a.length; j++) +
-        st = st+"<td>"+a[i][j]+"</td>"; +
-    st = st+"</tr>"; +
-  } +
-  st = st+"</table> &nbsp;"; +
- }else if (format=="text"){  +
-  var st="{n:"+n+", name:\""+classname+"_{"+a.length+","+k+"}\", size:"+a.length+", "; +
-  st=st+"num:"+k+", op:{\"cdot\":[\n"; +
-  for (var i=0; i<a.length; i++) { +
-    st = st+"["; +
-    for (var j=0; j<a.length; j++) +
-        st = st+a[i][j]+(j==a.length-1?"":","); +
-    st = st+"]"+(i==a.length-1?"]}},":",")+"\n"; +
-  } +
-  st = st+"\n"; +
-+
- return st; +
-+
-function checkRelation(A,rel) {//rel is a partial binary relation +
-    //Check that rel is transitive and compatible with the operations of A +
-    var op; +
-    var n = A.size; +
-    for (var x=0; x<n; x++) +
- for (var y=0; y<n; y++) +
-            if (rel[x][y]==1 && x!=y) { +
-                for (var z=x+1; z<n; z++) +
-                    if (rel[y][z]==1) +
-                        if (rel[x][z]==0) +
-                            return false; //not transitive +
- for (var r in A.op) { +
-    op = A.op[r]; +
-    if (op.length!=null) +
- if (op[0].length==null) { +
-    if (rel[op[x]][op[y]]==0) +
- return false; +
- } else +
-    for (var z=0; z<n; z++) { +
- if (rel[op[x][z]][op[y][z]]==0) +
-    return false; +
- if (rel[op[z][x]][op[z][y]]==0) +
-    return false; +
-    } +
-+
-    } +
-    return true+
-+
-function copyOf(arr) { +
-    var a = new Array(arr.length); +
-    for (var i=0; i<arr.length; i++) { +
-        a[i] = new Array(arr[i].length); +
-        for (var j=0; j<arr[i].length; j++) a[i][j] = arr[i][j]; +
-    } +
-    return a; +
-+
-function completeRelation(A,rel,i,j) { +
-    // find next i,j where rel[i][j]=2=undefined; for each val=0 or 1 +
-    // set rel[i][j]=val, check transitivity and compatibility +
-    // restore and return if no completetion,  +
-    // else call completeRelation(rel,i,j+1) +
-    var ok = true; +
-    while (ok && i<rel.length) { +
- while (j<rel.length && rel[i][j]!=2) j++; +
- if (j>=rel.length) { +
-    j=0;  +
-    i++;  +
- } else ok = false; +
-    } +
-    if (ok) congl[congl.length] = copyOf(rel); +
-    else for (var val=0; val<2; val++){ +
-    rel[i][j] = val; +
-    rel[j][i] = val; +
-    ok = checkRelation(A,rel); +
-    if (ok) completeRelation(A,rel,i,j+1); +
-    rel[i][j] = 2; +
-    rel[j][i] = 2; +
-+
-+
-function congruences(A) { +
-    // A is a finite algebra (JavaScript object) +
-    congl = []; +
-    var rel = new Array(A.size); +
-    for (var i=0; i<A.size; i++) { +
-        rel[i] = new Array(A.size); +
- for (var j=0; j<A.size; j++)  +
-    if (i!=j) rel[i][j] = 2; +
-    else rel[i][j]=1; +
-    } +
-    completeRelation(A,rel,0,0); +
-    return congl; +
-+
-function isSubrelation(R,S) { //assumes symmetry of relations +
-    for (var i=0; i<R.length; i++) +
- for (var j=i+1; j<R.length; j++) +
-    if (R[i][j]>S[i][j]) return false; +
-    return true; +
-+
-function conLatleq(cong) { //input list of 0-1-relations +
-  var leq = new Array(cong.length); +
-  for (var i=0; i<cong.length; i++) { +
-      leq[i] = new Array(cong.length); +
-      leq[i][i] = true; +
-      for (var j=0; j<cong.length; j++) +
-  if (i!=j) leq[i][j] = isSubrelation(cong[i],cong[j]); +
-  } +
-  return leq; +
-+
-function leq2uppercovers(rel) { +
-    var n = rel.length; +
-    var uc = new Array(n); +
-    for (var i=0; i<n; i++) { +
- uc[i] = []; +
-        for (var j=0; j<n; j++) +
-            if (rel[i][j] && i!=j) { +
- for (var k=0; k<n &&  +
- !(rel[i][k] && i!=k && rel[k][j] && k!=j); k++); +
- if (k==n) uc[i][uc[i].length] = j; +
-    } +
-    } +
-    return uc; +
-+
-function congblock(co,i) { +
-    var block = []; +
-    for (var j=0; j<co.length; j++) +
- if (co[i][j]==1) +
-    block[block.length] = j; +
-    return block; +
-+
-function cong2part(co) { +
-    var part = []; +
-    var flag = new Array(co.length); +
-    for (var i=0; i<co.length; i++) +
-        if (flag[i]==null) { +
-            cb = congblock(co,i); +
-            for (var j=0; j<cb.length; j++) flag[cb[j]]=true; +
-            part[part.length] = cb; +
-        } +
-    return part; +
-+
-function conLat(A) { +
-    var conA = {/*name:"Con("+A.name+")",*/ rel:{}}; +
-    var cl = congruences(A); +
-    conA.size = cl.length; +
-    conA.eltname = new Array(conA.size); +
-    for (var i=0; i<conA.size; i++) { +
-        conA.eltname[i] = cong2part(cl[i]).join(" | "); +
-    } +
-    conA.rel.uc = leq2uppercovers(conLatleq(cl)); +
-    return conA; +
-+
-function isSimple(A) { +
-    return congruences(A).length==2; +
-+
-function isSI(A) { +
-    var conA = conLat(A); +
-    return conA.rel.uc[0].length==1; +
-+
-/////////////////////////////////////////////////////////////////////// +
-classname="Band"; +
-counts=[]; +
-filtcounts=[]; +
-function initializeAlgebra(n) { // finite groupoid with n elements, {0,1,...,n-1} +
-    var alg = new Array(n); +
-    for (var i=0; i<n; i++) { +
- alg[i] = new Array(n); +
- for (var j=0; j<n; j++) +
-    alg[i][j] = (i==j?i:n); // all elements undefined (=n) +
-    } +
-    return alg; +
-+
-function checkAxioms(a) { +
-    var n,ok,x,y,z,xy,xyz; +
-    n = a.length; +
-    ok = true+
-    for (x=0; ok && x<n; x++) { +
-        for (y=0; ok && y<n; y++) { +
-            xy=a[x][y]; +
-            if (xy<n) { +
-//                ok = !(a[y][x]<n && xy!=a[y][x]); // check commutativity +
-                if (ok) { +
-                    for (z=0; ok && z<n; z++) { +
-                        xyz = a[xy][z]; +
-                        if (xyz<n) // check associativity +
-                            ok = !(a[y][z]<n && +
-                               a[x][a[y][z]]<n && xyz!=a[x][a[y][z]]); +
-    } +
-+
-    } +
-+
-    } +
-    return ok; +
-+
-function checkPermutations(alg) +
-    var i,j,ok,p,q,qi,aqi,a,equal; +
-    ok = true; +
-    var n = alg.length; +
-    for (p=0; ok && p<perms.length; p++) {//ok means alg <= qalg +
- q = perms[p]; +
- qi = invperms[p]; +
- equal = true; +
- for (i=0; equal && i<n; i++) {//equal means apij=qaij +
-    for (j=0; equal && j<n; j++) { +
- aqi = alg[qi[i]][qi[j]]; +
- a = alg[i][j]; +
- equal = (aqi<n && a==q[aqi]); +
- if (!equal) ok = (aqi==n || a<=q[aqi]); +
-    } +
-+
-    } +
-    return ok; +
-+
-function completeAlgebra(alg,i,j) { +
-    // find next i,j where alg[i][j]=n=undefined; for each val=0..n-1 +
-    // set alg[i][j]=val, check axioms and permutations +
-    // if ok, call completeAlg(alg,i,j+1) then restore and return +
-    var ok = true; +
-    var n = alg.length; +
-    while (ok && i<n) { +
- while (j<n && alg[i][j]<n) j++; +
- if (j>=n) { +
-    j = 0;  +
-    i++; +
- } else ok = false; +
-    } +
-    if (ok) { +
-        counts[alg.length-1]++; +
-        alglist[alglist.length] = {size:alg.length,op:{cdot:copyOf(alg)},num:counts[alg.length-1]}; +
-    } else for (var val=0; val<n; val++) { +
- alg[i][j] = val; +
- ok = checkAxioms(alg); +
- if (ok) ok = checkPermutations(alg); +
- if (ok) completeAlgebra(alg,i,j+1); +
-        alg[i][j] = n; +
-    } +
-+
-function nextPermutation(p) { +
-    var q=[]; +
-    for (var j=p.length-2; j>=0 && p[j]>p[j+1]; j--); +
-    if (j<0) return []; +
-    for (var k=0; k<j; k++) q[k]=p[k]; +
-    for (var k=p.length-1; p[j]>p[k]; k--); +
-    q[j]=p[k]; +
-    for (var i=p.length-1; i>j; i--) q[i]=p[j+p.length-i]; +
-    q[j+p.length-k]=p[j]; +
-    return q; +
-+
-function permutations(m,n) { // return list of permutations of {m,...,n} +
-    var perms = []; +
-    perms[0]=[]; +
-    for (var i=0; i<=n-m; i++) perms[0][i]=m+i; +
-    for (var i=0; perms[i].length>0; i++) { +
-        perms[i+1]=nextPermutation(perms[i]); +
-    } +
-    perms.length=perms.length-1; +
-    return perms; +
-+
-function inversePermutation(p) { +
-    var q=[]; +
-    for (var i=0; i<p.length; i++) +
- q[p[i]]=i; +
-    return q; +
-+
-function findAlgebras(size) { +
-    counts[size-1]=0; +
-    perms = permutations(0,size-1); +
-    invperms = []; +
-    for (var i=0; i<perms.length; i++) invperms[i]=inversePermutation(perms[i]); +
-    alg = initializeAlgebra(size); +
-    completeAlgebra(alg,0,0); +
-+
-function findAlgebrasRange(minsize,maxsize) { +
-    alglist = []; +
-    for (var i=minsize; i<=maxsize; i++) +
-        findAlgebras(i); +
-+
-function update(){ +
-  findAlgebrasRange(eval(document.getElementById('minsize').value), eval(document.getElementById('maxsize').value)); +
-+
-function filterAlgebras(As){ +
-    var Bs = []; +
-    for (var i=0; i<As[As.length-1].size; i++) filtcounts[i] = 0; +
-    simpleyes = document.getElementById("simpleyes").checked; +
-    simpleno = document.getElementById("simpleno").checked; +
-    siyes = document.getElementById("siyes").checked; +
-    sino = document.getElementById("sino").checked; +
-    for (var i=0; i<As.length; i++) { +
-        var add = (!simpleyes||!simpleno) && (!siyes||!sino); +
-        if (add && (simpleyes||simpleno)) { +
-            var simple = isSimple(As[i]); +
-            add = simpleyes && simple || simpleno && !simple; +
-        } +
-        if (add && (siyes||sino)) { +
-            var si = isSI(As[i]); +
-            add = siyes && si || sino && !si; +
-        } +
-        if (add) { +
-            Bs[Bs.length] = As[i]; +
-            filtcounts[As[i].size-1]++; +
-        } +
-    } +
-    filtlist = Bs; +
-    displayAlgebras(Bs); +
-+
-function displayAlgebras(As){ +
-    format = document.getElementById("format").value; +
-    algstr=(format=="text"?classname+"=[\n":""); +
-    for (var i=0; i<As.length; i++) +
-        algstr += algebraToString(As[i].op.cdot,As[i].num,i); +
-    document.getElementById("algebras").innerHTML=(format=="text"?"<textarea rows=\"35\">"+algstr.slice(0,algstr.length-3)+"];\n</textarea>":algstr); +
-    document.getElementById("counts").innerHTML="<a href=\"http://www.research.att.com/~njas/sequences/?q="+filtcounts.join(",+")+"&sort=0&fmt=0&language=english&go=Search\"><u><b>"+filtcounts.join(", ")+"</b></u></a>"; +
-+
-function searchAlgebras(){ +
-    findAlgebrasRange(eval(document.getElementById('minsize').value), eval(document.getElementById('maxsize').value)); +
-    filterAlgebras(alglist); +
-+
-function update(){ +
-    filterAlgebras(alglist); +
-+
-searchAlgebras(); +
-</script>+
</html> </html>