//masscalc.js
//3:54 PM 1/22/01
//copyright 2001 Bob Hanson, St. Olaf College
defmass=84
m=new Array()
f=new Array()
m["H"]=1.007825; f["H"]=.9999;
m["C"]=12.000000; f["C"]=.9890;
m["N"]=14.003074; f["N"]=.9963;
m["O"]=15.994915; f["O"]=.9976;
m["Cl"]=34.968853; f["Cl"]=.7577;
m["Br"]=78.918336; f["Br"]=.5069;
m["S"]=31.97207; f["S"]=0.950;
m["I"]=126,9004; f["I"]=1.00;
function doit(){
var mh=m["H"]
var mc=m["C"]
var mn=m["N"]
var mo=m["O"]
var mcl=m["Cl"]
var mbr=m["Br"]
var ms=m["S"]
var mi=m["I"]
var nh=parseInt(document.msinfo.nh.value)
var maxn=parseInt(document.msinfo.maxn.value)
var mass=document.msinfo.m_z.value
var cOK=document.msinfo.cOK.checked
var hOK=document.msinfo.hOK.checked
var oOK=document.msinfo.oOK.checked
var nOK=document.msinfo.nOK.checked
var clOK=document.msinfo.clOK.checked
var brOK=document.msinfo.brOK.checked
var sOK=document.msinfo.sOK.checked
var iOK=document.msinfo.iOK.checked
var Monly=document.msinfo.Monly[0].checked
if(mass==""){
alert("You must first indicate a mass")
return
}
if(mass<1 || mass>300){
alert("The mass requested is outside the range 12-300")
return
}
mass=Math.floor(eval(mass))
var intm=0
var exactm=0
var partc=0
var partn=0
var parto=0
var partcl=0
var partbr=0
var parts=0
var parti=0
var sout=""
var icount=0
var slist=(cOK?", C":"")+(hOK?", H":"")+(nOK?", N":"")+(oOK?", O":"")+(clOK?", Cl":"")+(brOK?", Br":"")+(sOK?", S":"")+(iOK?", I":"")
var selement=""
var i=slist.lastIndexOf(",")
if(slist.indexOf(",")!=i){
selement="s"
slist=slist.substring(0,i+(i==3?0:1))+" and"+slist.substring(i+1,slist.length)
}
if(slist==""){
alert("You must select one of the possible elements.")
return
}
for(C=0;C<=(cOK?mass/12:0);C++){
partc=C*12
for(N=0;N<=(nOK?(mass-partc)/14:0);N++){
partn=partc+N*14
for(O=0;O<=(oOK?(mass-partn)/16:0);O++){
parto=partn+O*16
for(Br=0;Br<=(brOK?(mass-parto)/79:0);Br++){
partbr=parto+Br*79
for(Cl=0;Cl<=(clOK?(mass-partbr)/35:0);Cl++){
partcl=partbr+Cl*35
for(S=0;S<=(sOK?(mass-partcl)/32:0);S++){
parts=partcl+S*32
for(I=0;I<=(iOK?(mass-parts)/127:0);I++){
parti=parts+I*127
H=mass-partcl
var maxh=C*2+2+N-Cl-Br-I
if(Monly && ((maxh-H) % 2))H=-1
if(!hOK && H>0)H=-1
if(H>=0 && H<=maxh && (!nh || H==nh) && (!maxn || N+O+Br+S+I+Cl<=maxn)){
icount++
exactm=C*mc+H*mh+N*mn+O*mo+Br*mbr+Cl*mcl+S*ms+I*mi
sout+=roundoff(exactm,4)+"\t"
sout+=the("C")+the("H")+the("N")+the("O")+the("Br")+the("Cl")+the("I")+the("S")
sout+="\n"
}
}
}
}
}
}
}
}
var s="There "+(icount==1?"is ":"are ")+(icount==0?"no":icount)+" possible "+(Monly?"molecular ion":"fragment")+(icount==1?"":"s")
s+="\nwith nominal mass "+mass
s+="\ninvolving only the element"+selement+" "+slist.substring(2,slist.length)
s+=(nh?" and having exactly "+nh+" H atoms":"")
s+=(maxn?" and having no more than "+maxn+" atoms other than C and H":"")
s+="\n\n"+sout
parent.fraDisp.document.info.list.value=s
}
function the(Element){
var e=eval(Element)
var subon=" "//
var suboff=""//
return (e>0?subon+Element+(e>1?e+suboff:""):"")
}
function roundoff(x,ndec)
{
//round x to ndec decimal places (+) fixed; (-) floating
//# 1410
if(x==0)return 0
if(ndec==0)return Math.round(x)
var xs=x+""
var i=(xs.indexOf("E") & xs.indexOf("e"))
if(ndec<0 && i<0)
{
var xs=roundoff(x*1e-100,-ndec)
var i=(xs.indexOf("E") & xs.indexOf("e"))
var e=(eval(xs.substring(i+1,xs.length))+100)
//# 1420
return xs.substring(0,i)+(e!=0?"E"+e:"")
}
if (i>0)
{
var s=roundoff(xs.substring(0,i),Math.abs(ndec)-1)+"E"+xs.substring(i+1,xs.length)
return s
}
i=xs.indexOf(".")
if (i<0)
//# 1430
{
xs=x+"."+"00000"+" "
i=xs.indexOf(".")
}
xs=xs.substring(0,i)+"."+xs.substring(i+1,i+1+ndec)
if(i==0) xs="0"+xs
if(xs.indexOf("-.")==0)xs="-0"+xs.substring(1,xs.length)
if(xs=="-")xs="0"
return xs
//# 1440
}
var stable="