mfind()
Description:
Search for positions of non-zero members in a vector or matrix.
Syntax:
mfind(A, n)
Note:
The external library function searches for positions of the first n non-zero members in vector or matrix A. It gets the position of the first non-zero member when parameter n is absent. If the total number of non-zero members is fewer than n, it returns positions of all non-zero, non-null members.
Search column by column when A is a matrix and return ordinal numbers of positions of non-zero members in the matrix.
Parameter:
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A n
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A vector or a matrix A positive integer |
Return value:
A sequence
Example:
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A |
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1 |
[0,,5,2,0,2,1,0] |
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2 |
=mfind(A1) |
Return position of the first non-zero member as parameter n is absent |
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3 |
=mfind(A1,3) |
Retrun positions of the first non-zero members
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4 |
=mfind(A1,10) |
Return positions of all non-zero members since the number of them in matrix A1 is fewer than n (here is 10) |
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5 |
[[1,0,2],[0,0,2],[0,4,7]] |
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6 |
=mfind(A5,3) |
As parameter A is a matrix, search for the first three non-zero members by column and the result are “1”,“4”,”2”, whose ordinal numbers of positions are 1,6,7 |
