Need to save values of a variable into a new column of asc file for each iteration of a for loop

Ndisvec=[.5 2 8 32 128]*10^11; %Set of density values

figure(1025)
clf(1025)
figure(1025)
hold on
set(gca, 'XScale', 'log', 'YScale', 'log')

%Riemann sum
x=[0:0025:1-.005];
I=[1:length(kf)];
for z=1:length(kf);
kfh=kf(z);
y=((x+(qtf/(2*kfh))).^2.*sqrt(1-x.^2)).^-1;
I(z)=sum(y)*.0025;
end

for z=1:length(Ndisvec)  
    Ndis=Ndisvec(z);
    tau=hb^3*(epo*epb*co)^2/(Ndis*meff*e^4*f^2)*16*pi*kf.^4./(I*sqrt(2));
    muDIS1=e*tau/meff;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    loglog(n(1,:)*10^-15,muDIS1(1,:)); %deleted 10^-4
end
figure(1025)

I need to print the values of muDIS1 into a new column for each iteration of the for loop (it will run 5 times). At the end i need an asc file which will have columns of data. I have been playing around with the fopen/fprintf functions but have had no luck. I made a for loop----- for muDIS1(z) and the fprintf just under muDIS1 fclose after i end the loop that didnt work

[Daniel Frisch]

Please give an example of the vector muDis1 for one row and the resulting wanted line in the asc file.

[Ahsan Khan]

Hi Sprry !

Under Jan Simons answer I have provided an example, his method saves my data but I am unable to format it properly.

Answer 1

[Jan]

Start with collecting the data:

muDIS1 = zeros(length(Ndisvec), ????)   % Set accordingly
for z = 1:length(Ndisvec)  
   Ndis      = Ndisvec(z);
   tau       = hb^3*(epo*epb*co)^2/(Ndis*meff*e^4*f^2)*16*pi*kf.^4./(I*sqrt(2));
   muDIS1(z, :) = e*tau/meff;
   loglog(n(1,:)*1e-15,muDIS1(z,:)); %deleted 10^-4
end

Now you can write the matrix at once using fopen, fprintf and flcose. Please try it and post the relevant code, if you still have problems.

PS: Note that 10^-15 is an expensive power operation, while 1e-15 is a cheap constant.

[Ahsan Khan]

muDIS1 = zeros(length(Ndisvec))
fileID=fopen('mymu_dis.asc','w');
for z=1:length(Ndisvec)  
    Ndis=Ndisvec(z);
    tau=hb^3*(epo*epb*co)^2/(Ndis*meff*e^4*f^2)*16*pi*kf.^4./(I*sqrt(2));
    muDIS1=e*tau/meff;
    length(muDIS1);
    muDIS1
     fprintf(fileID, '%5.2f\r\n, %5.2f\r\n,%5.2f\r\n,%5.2f\r\n,%5.2f\r\n,%d\r\n',muDIS1');
    loglog(n(1,:)*10^-15,muDIS1(1,:)); %deleted 10^-4
end
fclose(fileID);

The following code produces a file where all my data is put into a single column. What is need is the following, by need i mean it will be convenient for me For example lets say ndisvec= [1 2 3 4 5]

I need my file to have

1 2 3 4 5 
# 
#
#
.
.
.

Where the hashtages and dots are data (each column should end up with 61 rows).

Surely, your method saved all my data, but i couldn't format it properly. PS. Ill keep that in mind for when I clean up my codes at the end !

[Jan]

If you do not want a line break after each value, do not insert a line break after each value:

fprintf(fileID, '%5.2f, %5.2f, %5.2f, %5.2f, %5.2f, %d\n', muDIS1);

Omit the useless code "length(muDIS1); muDIS1".

You can either insert the output to the file into the loop, or create matrix as shown in my code and write the file at once, which is expected to be faster.

Using '\r\n' instead of '\n' is needed, if you really want to display the file in the Windows NotePad. All other editors accept '\n' directly for decades.

[Ahsan Khan]

Thanks! I'm still new to matlab, never did much coding until now