Saving for loop output ever iteration to plot graph

clc;
clear;
N=0;
for sCT=0.0001:0.0001:0.0038;

%sF=steel force 
%sCT=strain top concrete

    for c=0.1:0.01:500;    
   
    %sS=strain steel
    sS1= (sCT*(abs(c-50)))/c;
    sS2= (sCT*(abs(c-250)))/c;
    sS3= (sCT*(abs(c-450)))/c;
    %sF=steel force, unit kN
   sF1=sS1*200000*3*pi*15*15/1000;
        if  sF1>420;
            sF1=420;
        else 
        end
    sF2=sS2*200000*2*pi*15*15/1000;
    if  sF2>420;
            sF2=420;
        else 
        end
    sF3=sS3*200000*3*pi*15*15/1000;
    if  sF3>420;
            sF3=420;
        else 
        end
    %cF=concrete force, unit kN
    %TcF=Total concrete force, unit kN
    %cS=concrete stress, unit MPa
    %C=strain concrete
        TcF=0;
        for i=1:1:100;
        y=(c*(i-1/2))/100;
        sC=(sCT*abs(c-y))/c;
        
            if 0<sC<=0.002;
             
             cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
             
             elseif 0.002<sC<=0.0038;
             cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
             else 
             cS=0;      
      
            end
         
            cF=cS*500*c/100000;   
            TcF=TcF+cF;
      
        
        end 
       
        
    
    if -1 <(sF1 + sF2 + sF3 + TcF -N) & (sF1 + sF2 + sF3 + TcF -N) <1;
        
        TMc=0;
        for i=1:1:100;
        y=(c*(i-1/2))/100;
        sC=(sCT*abs(c-y))/c;
        
            if 0<sC<=0.002;
             
             cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
             
             elseif 0.002<sC<=0.0038;
             cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
             else 
             cS=0;      
      
            end
         
            cF=cS*500*c/100000; 
        
        Mc=(cF*abs(250-y))/1000;
        TMc=TMc+Mc;
        
        end
        
        TMc=0.2*sF1-0.2*sF3+TMc;
        
        break;
        
    elseif -1 <(sF1 + sF2 - sF3 + TcF -N) & (sF1 + sF2 - sF3 + TcF -N) <1;
        
            TMc=0;
        for i=1:1:100;
        y=(c*(i-1/2))/100;
        sC=(sCT*abs(c-y))/c;
        
            if 0<sC<=0.002;
             
             cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
             
             elseif 0.002<sC<=0.0038;
             cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
             else 
             cS=0;      
      
            end
         
            cF=cS*500*c/100000; 
        
        Mc=(cF*abs(250-y))/1000;
        TMc=TMc+Mc;
        
        end
        
        TMc=0.2*sF1+0.2*sF3+TMc;
        
        break;
        
    elseif -1 <(sF1 - sF2 - sF3 + TcF -N) & (sF1 - sF2 - sF3 + TcF -N) <1;
        
            TMc=0;
        for i=1:1:100;
        y=(c*(i-1/2))/100;
        sC=(sCT*abs(c-y))/c;
        
            if 0<sC<=0.002;
             
             cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
             
             elseif 0.002<sC<=0.0038;
             cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
             else 
             cS=0;      
      
            end
         
            cF=cS*500*c/100000; 
        
        Mc=(cF*abs(250-y))/1000;
        TMc=TMc+Mc;
        
        end
        
        TMc=0.2*sF1+0.2*sF3+TMc;
        
        break;
        
    elseif -1 <(-sF1 - sF2 - sF3  -N) & (-sF1 - sF2 - sF3  -N) <1;
        
       
        
        TMc=-0.2*sF1+0.2*sF3;
        
        break;       
 
        
    else;
        
        
    
    end
    end    
   K= [sCT/(c*0.001)];
  
   plot(K,TMc);
   grid on        
     
    
end

Guys can u help me? i cannot save the output of loop and plot the graph.

Answer 1

[Image Analyst]

Index the x and y so that they're arrays, not a single scalar. Then put the call to plot outside the loops.

[Ege Çetiner]

i did it but it says ''Index in position 1 is invalid. Array indices must be positive integers or logical values.''

[Image Analyst]

You used the wrong value for the index. It should be a number like 1,2,3,4,etc. Not zero, a fractional number, or a negative number.

See the FAQ:

https://matlab.fandom.com/wiki/FAQ#.22Subscript_indices_must_either_be_real_positive_integers_or_logicals..22

[Ege Çetiner]

Sir, thank you for your kind response but i cannot make it integer since i need to use this values. The question is, isnt that possible to use decimal values to plot a graph? if yes, how can i do it or how can i convert this code to it?

[Image Analyst]

You can't do stuff like

if 0<sC<=0.002

I fixed it below (I think - check it).

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format short g;
format compact;
fontSize = 18;
fprintf('Beginning to run %s.m ...\n', mfilename);

N=0;
counter = 0;
for sCT=0.0001:0.0001:0.0038
	fprintf('sCT = %.4f\n', sCT);
	%sF=steel force
	%sCT=strain top concrete
	for c=0.1:0.01:500
		%fprintf('    c = %.4f\n', c);
		%sS=strain steel
		sS1 = (sCT*(abs(c-50)))/c;
		sS2 = (sCT*(abs(c-250)))/c;
		sS3 = (sCT*(abs(c-450)))/c;
		%sF=steel force, unit kN
		sF1=sS1*200000*3*pi*15*15/1000;
		if  sF1>420
			sF1=420;
		end
		sF2=sS2*200000*2*pi*15*15/1000;
		if  sF2>420
			sF2=420;
		end
		sF3=sS3*200000*3*pi*15*15/1000;
		if  sF3>420
			sF3=420;
		end
		%cF=concrete force, unit kN
		%TcF=Total concrete force, unit kN
		%cS=concrete stress, unit MPa
		%C=strain concrete
		TcF=0;
		for i=1:1:100
			y=(c*(i-1/2))/100;
			sC=(sCT*abs(c-y))/c;
			if 0<sC<=0.002
				cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
			elseif 0.002<sC<=0.0038
				cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
			else
				cS=0;
			end
			cF=cS*500*c/100000;
			TcF=TcF+cF;
		end
		
		if -1 <(sF1 + sF2 + sF3 + TcF -N) && (sF1 + sF2 + sF3 + TcF -N) < 1
			TMc=0;
			for i=1:1:100
				y=(c*(i-1/2))/100;
				sC=(sCT*abs(c-y))/c;
				
				if (0 < sC) && (sC <=0.002)
					cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
				elseif 0.002<sC<=0.0038
					cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
				else
					cS=0;
				end
				cF=cS*500*c/100000;
				Mc=(cF*abs(250-y))/1000;
				TMc=TMc+Mc;
			end
			TMc=0.2*sF1-0.2*sF3+TMc;
			break;
			
		elseif -1 <(sF1 + sF2 - sF3 + TcF -N) && (sF1 + sF2 - sF3 + TcF -N) <1
			TMc=0;
			for i=1:1:100
				y=(c*(i-1/2))/100;
				sC=(sCT*abs(c-y))/c;
				
				if (0 < sC) && (sC <=0.002)
					cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
				elseif (0.002 < sC) && (sC <=0.0038)
					cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
				else
					cS=0;
				end
				cF=cS*500*c/100000;
				Mc=(cF*abs(250-y))/1000;
				TMc=TMc+Mc;
			end
			TMc=0.2*sF1+0.2*sF3+TMc;
			break;
		elseif -1 <(sF1 - sF2 - sF3 + TcF -N) && (sF1 - sF2 - sF3 + TcF -N) <1
			TMc=0;
			for i=1:1:100
				y=(c*(i-1/2))/100;
				sC=(sCT*abs(c-y))/c;
				
				if (0 < sC) && (sC <=0.002)
					cS=0.85*25*(2*(sC/0.002)-((sC/0.002)*(sC/0.002)));
				elseif (0.002 < sC) && (sC <=0.0038)
					cS=0.85*25-((0.15*0.85*25*(sC-0.002))/(0.0038-0.002));
				else
					cS=0;
				end
				cF=cS*500*c/100000;
				Mc=(cF*abs(250-y))/1000;
				TMc=TMc+Mc;
			end
			TMc=0.2*sF1+0.2*sF3+TMc;
			break;
			
		elseif -1 <(-sF1 - sF2 - sF3  - N) && (-sF1 - sF2 - sF3 - N) < 1
			TMc=-0.2*sF1+0.2*sF3;
			break;
		end
	end
	K = [sCT/(c*0.001)];
	% Log this point.
	counter = counter + 1;
	xAll(counter) = K;
	yAll(counter) = TMc;
	% Plot it
	plot(K, TMc, 'b.', 'MarkerSize', 25);
	grid on
	hold on;
	drawnow;
end
title('TMc vs. K', 'FontSize', fontSize);
xlabel('K', 'FontSize', fontSize);
ylabel('TMc', 'FontSize', fontSize);
% Draw lines in between the points.
plot(xAll, yAll, 'r-', 'LineWidth', 2);
hold off;

[Ege Çetiner]

Thank you, sir ^^