Can someone explain to me how this function works?

Question

Andrew Ardolino 2014-11-17

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/163122-can-someone-explain-to-me-how-this-function-works

回答： Roger Stafford 2014-11-18

function finElemNext = nextTemps( finElem )
% This function will create a new fin element array by averaging the 
% temperatures surrounding each element location
% uses finElemNext = nextTemps( finElem )
global maxDelta
maxDelta=0;
newFin=zeros(numRows,numCols);
for i = 2 : (numRows - 1)
for j = 2 : (numCols - 1)
    t_original=finElem(i,j);
     if t_original~=steamTemp
        t_row_above=finElem(i-1,j);
        t_row_below=finElem(i+1,j);
        t_col_left=finElem(i,j-1);
        t_col_right=finElem(i,j+1);
        newFin(i,j)=mean([t_original,t_row_above,t_row_below,t_col_left,t_col_right]);
        delta=finElem(i,j)-newFin(i,j);
        if delta>maxDelta
            maxDelta=delta;
        end
    else
         newFin(i,j)=finElem(i,j);
    end
end
end
finElemNext=setupFin(newFin);
end

I just need to be able to explain how this program calculates the data for this function. Thanks in advance :)

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Azzi Abdelmalek 2014-11-17

Explain what?

Andrew Ardolino 2014-11-17

Just in normal language how the function calculates the next temperature for a single cell in the fin array.

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Answer 1

Roger Stafford 2014-11-18

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/163122-can-someone-explain-to-me-how-this-function-works#answer_159284

The complete 'nextTemps' function is not shown, so we are left guessing about some parts of it. For example we can only guess that 'numRows' and 'numCols' are the numbers of rows and columns of 'finElem'.

Each of the elements of 'finElem' which are not equal to 'steamTemp' and which are not along its borders are replaced in 'newElem' by the mean (average) of itself and its four nearest neighbors. Before 'setupFin' is called, the borders of 'newElem' are left as zeros. There is no way to tell what happens after 'setupFin' is called, but apparently the original border values of 'finElem' are permanently lost. A record is kept in 'maxDelta' of the maximum decrease occurring from 'finElem' to 'newElem', but this maximum does not appear to be returned by 'nextTemps'.

Taken all-in-all, this function, 'nextTemps', or at least its presentation here, is altogether unsatisfactory.