How can I resolve this error?

I have written this code:

figure 

name = 'cap_';

vector = {'T0' 'T1' 'T2' 'T3' 'T4' 'T5' 'T6' 'T7' T8' 'T9'};

for i=1:length(vector)

name_1 = strcat(name, vector(i));

name_1 = char(name_1);

plot(x, sscanf(name_1, '%s'), 'y');

hold on

name_1 = [];
end

When I run this code I receive this message error: There is no cap_T1 property on the Line class

If I use:

plot(x, sscanf(name_1, '%s'))  I receive this other message: Error in color/linetype argument

Help me please.

Thanks

[Walter Roberson]

What would you like the code to do?

[Gianmarco Polizia]

Hello Walter thanks for attention payed to my question

I would like that the for loop substitutes these code lines:

plot(frequency_1, cap_1)

hold on

plot(frequency_2, cap_2)

.

.

.

plot(frequency_10, cap_10)

[Walter Roberson]

... Don't do that!

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

[Gianmarco Polizia]

Writing this: plot(x,sscanf(y)) is like to use eval()?

[Jan]

@Gianmarco: sscanf does not do, what you assume. It does not evaluate a variable with the name given in the string, but parses the string itself and tries to convert it to a number:

s = '89.81'
v = sscanf(s, '%f');

Now s=89.81. What you want to do instead is evaluate a string as a variable, and as explained in the links posted by Walter, this is a shot in your knee. Instead of creating:

vector = {'T0' 'T1' 'T2' 'T3' 'T4' 'T5' 'T6' 'T7' T8' 'T9'};

use:

vector = {T0, T1, T2, T3, T4, T5, T6, T7, T8, T9};

Or even better do not create the set of variables at all, but store them in an array directly. Then accessing them in a loop is easy by using an index.

[Gianmarco Polizia]

@Jan I don't understand the difference between do not create the set of variables at all and store them in an array directly.

In the first case, how is the code? And how is the code in the second case?

Thanks

[Walter Roberson]

It is better to avoid creating numbered variables and to create indexed variables instead. But if you do for some reason have numbered variables then instead of creating variable names at run-time, it is better to take the one-time hit of putting the variables together into an array and after that index the array.

frequencies = {frequency_1, frequency_2, frequency_3, frequency_4, frequency_5, frequency_6, frequency_7, frequency_8, frequency_9, frequency_10};
caps = {cap_1, cap_2, cap_3, cap_4, cap_5, cap_6, cap_7, cap_8, cap_9, cap_10};
names = cellstr( num2str((1:10).', 'line #%d') );

for K = 1 : length(frequencies)
  plot(frequencies{K}, caps{K});
  hold on
end

legend(names);