33 views (last 30 days)

For my project, I am calculating the half-life of an organism based on radioactive decay. My code is below. The problem I am experiencing is that he figure only has one point plotted. If someone could explain how to fix this so my entire function would be plotted, that would be greatly appreciated.

function Project

clc, clear

P=menu ('Please choose the element', 'Pm-145', 'Po-209', 'Ra-226', 'Ac-227', 'Am-243', 'Bk-247', 'Cf-251', 'C-14');

switch P %P=element found in sample through AMS

case 1 % Promethium-145

t=17.4;

case 2 % Polonium-209

t=102;

case 3 % Radium-226

t=1600;

case 4 % Actinium-227

t=21.77;

case 5 % Americium-243

t=7370;

case 6 % Berkelium-247

t=1380;

case 7 % Californium-251

t=898;

case 8 % Carbon-14

t=5730;

end

N=input ('Please enter the remaining percentage of substance: \n');

while N<=0 || N>=100 %N=percentage of element found through AMS

fprintf ('Incorrect input. Please try again. \n');

N=input ('Please enter the remaining percentage of substance: \n');

end

clc

age=(((log((N)/(100)))/(-0.693))*t);

fprintf ('The age of your organism is shown below: \n');

fprintf (' %s years',age);

n=length(N);

for i=1:n

plot(age(i), N(i), '*', 'MarkerSiz', 10)

xlim([0 inf])

ylim([0 100])

pause(.01)

hold all

xlabel(strcat('Years passed = ', num2str(age(i))))

ylabel(strcat('Percentage remaining =', num2str(N(i))))

title ('Radioactice Decay')

grid on

end

end

Thanks!

the cyclist
on 16 Jul 2019

Your variable N is a single value -- a scalar. (It is an array of length 1.) You then define n to be the length of that array. So n = 1.

Then, you plot in a for loop that goes from 1 to n. But that's from 1 to 1. So, you get one point.

Sign in to answer this question.

Opportunities for recent engineering grads.

Apply Today
## 6 Comments

## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725033

⋮## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725033

## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725040

⋮## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725040

## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725055

⋮## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725055

## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725066

⋮## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725066

## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725071

⋮## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725071

## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725081

⋮## Direct link to this comment

https://nl.mathworks.com/matlabcentral/answers/471964-problem-using-hold-on-in-a-for-loop#comment_725081

Sign in to comment.