need plotting help with matrix and loops

Question

neil whitesell 2020-11-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/659093-need-plotting-help-with-matrix-and-loops

评论： neil whitesell 2020-11-30

i have a program that spits out a 101 row complex matrix, but i need to retrieve only the 50th row (one less than the 'middle') and save it into the plot, then re-do the loop to gather the same vallue with a different variable each time, to plot the change in the result. i am new to matlab and need some help fixing this error please

the variable i am snatching is 'cur' and i'd like to plot it on y axis with 'imp' on the x-axis.

(if you're curious this is an antenna program to graph the impedance and current as the 'thickness' of the antenna changes)

close all

clc

addpath c:\antennas\ewa;

l=.68;

a=(.00002);

ker='a';

basis='d';

E=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,100000,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]

x=(0:1:100);

for a=.00002:.00001:.01

pfield(l,a,E,ker,basis);

cur=abs(ans(50))

imp=100/cur

plot(imp,cur);

hold on

end

hold off

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neil whitesell 2020-11-23

the pfield() program spits out a complex matrix of the same size as the input 'E', the bit where i specify 'ans' is the output of that pprogram

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Answer 1

Rohit Pappu 2020-11-26

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/659093-need-plotting-help-with-matrix-and-loops#answer_556828

在 MATLAB Online 中打开

Minor refactoring of the above code

close all
clc
clf %%Clear the figure window
addpath c:\antennas\ewa;
l=.68;
a=(.00002);
ker='a';
basis='d';
E=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,100000,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
x=(0:1:100);
hold on
for a=.00002:.00001:.01
    output = pfield(l,a,E,ker,basis); %% Using ans in a script is not a good idea
    cur=abs(output(50));
    imp=100/cur;
    plot(imp,cur,'Marker','*'); %% Plots each point as an asterix *
end
hold off