Why does the first value in loop get overwritten

Question

Sargondjani 2012-12-8

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56065-why-does-the-first-value-in-loop-get-overwritten

For some reason when fi == 1, NPV_list(1,1) is inserted correctly, but when fi=2 the value gets overwritten, which i dont understand... at all. This is the code:

clear all;
clc;
Fi = [0,0.8:0.05:1];
T = 160;
NPV_list = NaN(length(Fi),1);
for fi = 1:length(Fi);
    fi
    F = Fi(fi);
    load (['res_us_v15_',num2str(T),'_',num2str(100*F)]) 
    NPV_list(fi,1) = us.sim.NPV_Pb_Wlth_avg
    clearvars -except NPV_list Fi T;
end

Can someone explain this? This is the output for first 2 iterations:

      fi =
           1
    NPV_list =
        9.9570
           NaN
           NaN
           NaN
           NaN
           NaN
    fi =
         2
    NPV_list =
        9.8664
           NaN
           NaN
           NaN
           NaN
           NaN

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Answer 1

per isakson 2012-12-8

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编辑：per isakson 2012-12-8

在 MATLAB Online 中打开

No, I cannot explain. However, what else is in the files you load? The clearvars looks scary to me.

My function, cssm, works:

    >> cssm()
    ans =
       101   102   103   104   105   106

where

    function    NPV_list = cssm()
        Fi = [0,0.8:0.05:1];
        T = 160;
        us = [ 101 : 109 ];
        NPV_list = NaN(1,length(Fi));
        for fi = 1:length(Fi);
            fi;
            F = Fi(fi);
            NPV_list(1,fi) = us(fi);
            clearvars -except NPV_list Fi T us;
        end
    end

.

Doc says:

S = load( filename, variables );

Try

S = load( filename, 'us' );

and remove clearvars.

Last, check whether there is a variable in the loaded file that explains the behavior you see.

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Answer 2

Richard 2012-12-8

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编辑：Richard 2012-12-8

在 MATLAB Online 中打开

Try

Fi = [0,0.8:0.05:1];
T = 160;
NPV_list = NaN(length(Fi),1);
for fi = 1:length(Fi);
    F = Fi(fi);
    load (['res_us_v15_',num2str(T),'_',num2str(100*F)]) 
    NPV_list(fi,1) = us.sim.NPV_Pb_Wlth_avg
end
clearvars -except NPV_list Fi T;