Re: Adding a value to the cell of a matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg76062] Re: Adding a value to the cell of a matrix*From*: Ray Koopman <koopman at sfu.ca>*Date*: Tue, 15 May 2007 05:05:29 -0400 (EDT)*References*: <f23qem$o48$1@smc.vnet.net>

On May 12, 12:30 am, newbie <purete... at gmail.com> wrote: > I have a matrix of values that i am searching for a specific value > in and i want to count the number of occurances in each column. > which i can do but not in a loop. I want to be able to use a > matrix to store the number of occurances so i can put it in a loop. > I already have a loop that finds the values and just adds them to > a value i created. do you know how i can add +1 to the cell of a > matrix? When i try to do this it says the values are protected. > i tried unprotecting them but couldn't get that to work. > > any ideas? > > Here is the code i am using for the search > > Orderedcellcycle = OverExpressed; (* Dimensions {200, 18} *) > > l = matrix1; (* {5164, 18} *) > > Do[l[[All,i]] = Ordering[matrix1[[All,i]]], {i,1,18}]; > > Do[Do[Orderedcellcycle[[i,j]] = annotations[[l[[i,j]],6]], > {i,1,200}], > {j,1,18}]; > > gcounter = scounter = gmcounter = mgcounter = sgcounter = 0; > > Do[Do[If[Orderedcellcycle[[i,j]] == "G1", > gcounter = gcounter + 1, gcounter = gcounter + 0], > {i,1,200}]; > Do[If[Orderedcellcycle[[i,j]] == "S", > scounter = scounter + 1, scounter = scounter + 0], > {i,1,200}]; > Do[If[Orderedcellcycle[[i,j]] == "S/G2", > sgcounter = sgcounter + 1, sgcounter = sgcounter + 0], > {i,1,200}]; > Do[If[Orderedcellcycle[[i,j]] == "G2/M", > gmcounter = gmcounter + 1, gmcounter = gmcounter + 0], > {i,1,200}]; > Do[If[Orderedcellcycle[[i,j]] == "M/G1", > mgcounter = mgcounter + 1, mgcounter = mgcounter + 0], > {i,1,200}], > {j,1,18}] This will give five 18-element lists of counts. Although "l" is {5164, 18}, you use only the first 200 elements in each column, so those are the only ones I put into "L". It's much easier to work with rows than columns. L = Ordering[#,200]& /@ Transpose @ matrix1; (*{5164,18}->{18,200}*) orderedcellcycle = annotations[[#,6]]& /@ L; (* {18,200} *) gcount = Count[#,"G1" ]& /@ orderedcellcycle; (* {18} *) scount = Count[#,"S" ]& /@ orderedcellcycle; (* {18} *) sgcount = Count[#,"S/G2"]& /@ orderedcellcycle; (* {18} *) gmcount = Count[#,"G2/M"]& /@ orderedcellcycle; (* {18} *) mgcount = Count[#,"M/G1"]& /@ orderedcellcycle; (* {18} *) If you have many patterns for which you need counts, you might want to do something like this, which gives a {5, 18} matrix of counts: patternlist = {"G1", "S", "S/G2", "G2/M", "M/G1"}; countmatrix = Outer[Count[#2,#1]&, patternlist, orderedcellcycle, 1];