MATLAB Examples

inrealquad documentation

This function returns the elements in a 2D matrix bounded by the quandrangle encompassing all real values in the input matrix.

Contents

Syntax

tf = inrealquad(A)
[rows,cols] = inreqalquad(A)
Atrim = inrealquad(A,'trim')

Description

tf = inrealquad(A) returns a logical matrix tf the size of 2D matrix A. tf is true for all elements in A bounded by the quandrangle containing all real values in A.

[rows,cols] = inrealquad(A) returns the rows and columns of A containing all real values in A.

Atrim = inrealquad(A,'trim') trims A to the quadrangle containing all finite values in A.

Example

Here is some sample data A with two rows and one column of NaNs. Also a few extra NaNs in the middle to make it clear how this function works:

A = rand(8,5);
A(:,1) = NaN;
A([1 2 7],:) = NaN;
A(5,3) = NaN;
A(3:4,5) = NaN;

The sample matrix A looks like this:

A
A =
       NaN       NaN       NaN       NaN       NaN
       NaN       NaN       NaN       NaN       NaN
       NaN    0.0855    0.2373    0.6791       NaN
       NaN    0.2625    0.4588    0.3955       NaN
       NaN    0.8010       NaN    0.3674    0.3354
       NaN    0.0292    0.5468    0.9880    0.6797
       NaN       NaN       NaN       NaN       NaN
       NaN    0.7303    0.2316    0.8852    0.7212

Get a logical matrix the size of A which shows the quadrangle of finite values in A:

tf = inrealquad(A)
tf =
     0     0     0     0     0
     0     0     0     0     0
     0     1     1     1     1
     0     1     1     1     1
     0     1     1     1     1
     0     1     1     1     1
     0     1     1     1     1
     0     1     1     1     1

Alternatively, you can get rows and columns corresponding to the quadrangle in A containing all real data in A:

[rows,cols] = inrealquad(A)
rows =
     0
     0
     1
     1
     1
     1
     1
     1
cols =
     0     1     1     1     1

Or you can trim A to the quadrangle that contains all real values in A:

Atrimmed = inrealquad(A,'trim')
Atrimmed =
    0.0855    0.2373    0.6791       NaN
    0.2625    0.4588    0.3955       NaN
    0.8010       NaN    0.3674    0.3354
    0.0292    0.5468    0.9880    0.6797
       NaN       NaN       NaN       NaN
    0.7303    0.2316    0.8852    0.7212

Author Info

This function was written by Chad A. Greene of the University of Texas at Austin's Institute for Geophysics (UTIG), September 2015.