Forming loop to perform same action
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I am having problem creating the loop for the task.
Thres = 0.17;
istrue1= ((x>=928 & x<=1139) & y>=Thres)|((x>=2527 & x<=2856) & y>=Thres)|((x>=4113 & x<=4376) & y>=Thres)|((x>=5464 & x<=5643) & y>=Thres)|((x>=7254 & x<=7604) & y>=Thres);
TP = sum(istrue1);
Using the command I can find out the value of TP for a particular value of thres. But I want to vary the value of thres from 0:0.1:1 and want to get 10 values of TP simultaneously rather than changing Thres each time. I know it is easy but not for me. Please help.
采纳的回答
dpb
2020-4-4
Thres = 0.17;
istrue1=((x>= 928 & x<=1139) & y>=Thres) | ...
((x>=2527 & x<=2856) & y>=Thres) | ...
((x>=4113 & x<=4376) & y>=Thres) | ...
((x>=5464 & x<=5643) & y>=Thres) | ...
((x>=7254 & x<=7604) & y>=Thres);
is same as
istrue1=(x>= 928 & x<=1139 | ...
x>=2527 & x<=2856 | ...
x>=4113 & x<=4376 | ...
x>=5464 & x<=5643 | ...
x>=7254 & x<=7604) & y>=Thres);
Is place for my "syntactic sugar" helper utility iswithin...
istrue1=(iswithin(x, 928,1139) | ...
iswithin(x,2527,2856) | ...
iswithin(x,4113,4376) | ...
iswithin(x,5464,5643) | ...
iswithin(x,7254,7604)) & y>=Thres);
to reduce the clutter of all the tests conditions by moving into the function.
function flg=iswithin(x,lo,hi)
% returns T for values within range of input
% SYNTAX:
% [log] = iswithin(x,lo,hi)
% returns T for x between lo and hi values, inclusive
flg= (x>=lo) & (x<=hi);
end
2 个评论
SUBHAJIT KAR
2020-4-5
dpb
2020-4-5
As shown, it doesn't replace the individual tests, just hides the clutter.
I don't see any brilliant vectorizing available here; could build a function that looped over an array of lo, hi intervals or write the loop construct at this level would probably be my choice if there are variable numbers of regions and do this much. It's a situation haven't run into in my own code so hadn't attacked it, specifically.
更多回答（1 个）
Image Analyst
2020-4-4
编辑：Image Analyst
2020-4-4
Rather than be so complicated, break it into parts, like
term1 = (x>=928 & x<=1139)
term2 = y>=Thres
term3 = (x>=2527 & x<=2856)
and so on. Then look at the size and values of each term. This is just basic debugging... Then
put Thresh into a loop
Thres = [0 : 0.1 : 1];
for k = 1 : length(Thres)
thisThres = Thres(k);
istrue1 = ...... function thisThresh instead of Thres
end
4 个评论
SUBHAJIT KAR
2020-4-4
编辑：SUBHAJIT KAR
2020-4-4
Image Analyst
2020-4-4
编辑：Image Analyst
2020-4-4
You can preallocate using the lengths of the x and Thres vectors like this:
z = zeros(length(Thres), length(x));
By the way, the length of Thres is not 10:
>> length( 0:0.1:1 )
ans =
11
SUBHAJIT KAR
2020-4-5
SHAIK
2024-2-26
from the above code what is y.
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