# Blank figures using plot

2 views (last 30 days)
Ivaylo Ivanov on 19 Jan 2020
Commented: Ivaylo Ivanov on 20 Jan 2020
I am running the following code and when the figures pop-up, they are blank without any lines.
I have tried running the Matlab in the software mode, thinking that the problem is in the OpenGL, but nothing changed.
So the error must be in the code , but I cannot figure out where. I appreacate any help on this, as I am stuck..
c1=3.74*10^8;
c2=1.44*10^4;
T1=30;
T2=90;
T3=120;
a1=0;
a2=0;
a3=0;
max1=0;
max2=0;
max3=0;
figure(1);
for a=0:0.01:300
M=c1/((a^5)*(exp(c2/(a*T1))-1));
plot(a,M,'b')
if M>max3
max3=M; a3=a;
end
hold on
end
figure(2);
for a=0:0.01:80
M=c1/((a^5)*(exp(c2/(a*T2))-1));
plot(a,M,'r')
if M>max2
max2=M; a2=a;
end
hold on
end
figure(3);
for a=0:0.01:80
M=c1/((a^5)*(exp(c2/(a*T3))-1));
plot(a,M,'g')
if M>max1
max1=M; a1=a;
end
hold on
end

Image Analyst on 19 Jan 2020
Try this:
clc
clear all
close all
c1 = 3.74*10^8;
c2 = 1.44*10^4;
T1 = 30;
T2 = 90;
T3 = 120;
a1 = 0;
a2 = 0;
a3 = 0;
max1 = 0;
max2 = 0;
max3 = 0;
subplot(1, 3, 1);
a = 0:0.01:300;
M = zeros(1, length(a));
fprintf('Starting loop #1 to compute %d values.\n', length(a));
for k = 1 : length(a)
M(k) = c1/((a(k)^5)*(exp(c2/(a(k)*T1))-1));
if M(k)>max3
max3 = M(k);
a3 = a;
end
hold on
end
plot(a, M, 'b-', 'LineWidth', 2)
grid on;
xlabel('a', 'FontSize', 15);
ylabel('M', 'FontSize', 15);
drawnow;
subplot(1, 3, 2);
a = 0:0.01:80;
M = zeros(1, length(a));
fprintf('Starting loop #2 to compute %d values.\n', length(a));
for k = 1 : length(a)
M(k) = c1/((a(k)^5)*(exp(c2/(a(k)*T2))-1));
if M(k) > max2
max2 = M(k);
a2 = a;
end
hold on
end
plot(a, M, 'r-', 'LineWidth', 2)
grid on;
xlabel('a', 'FontSize', 15);
ylabel('M', 'FontSize', 15);
drawnow;
subplot(1, 3, 3);
a = 0:0.01:80;
M = zeros(1, length(a));
fprintf('Starting loop #3 to compute %d values.\n', length(a));
for k = 1 : length(a)
M(k) = c1/((a(k)^5)*(exp(c2/(a(k)*T3))-1));
if M(k) > max1
max1 = M(k);
a1 = a;
end
hold on
end
darkGreen = [0, 0.5, 0];
plot(a, M, 'g', 'Color', darkGreen, 'LineWidth', 2)
grid on;
xlabel('a', 'FontSize', 15);
ylabel('M', 'FontSize', 15);
Command window shows:
Starting loop #1 to compute 30001 values.
Starting loop #2 to compute 8001 values.
Starting loop #3 to compute 8001 values.

#### 1 Comment

Ivaylo Ivanov on 20 Jan 2020
Thank you for the code and your work. I would never though on it from this side.