The SelectNonNumeric function selects non-numeric items from X and returns them in a new data sample. Note, that an expression X is considered non-numeric if $\mathrm{evalf}\left(X\right)$ does not return a floating-point number. Numeric items are discarded in the newly created data sample.

The first parameter X is a data sample - given as e.g. a Vector.

The RemoveNonNumeric function does the opposite of SelectNonNumeric. It removes the non-numeric values from X.

The options argument can contain one or more of the options shown below.

exclude=infinity, undefined, or [infinity, undefined] -- By default, undefined and infinity are considered non-numeric. This can be changed by adding infinity or undefined or both to the exclude list. Thus, exclude=undefined means that infinity should still be considered numeric but undefined should not.

$\mathrm{with}\left(\mathrm{Statistics}\right)\:$

$A≔\mathrm{Array}\left(\left[3\,3\,1\,a\,b\,a\,\mathrm{\pi }\,\sin \left(1\right)\,\mathrm{undefined}\,\mathrm{\infty }\right]\right)$

$A≔\left[\begin{array}{cccccccccc}3& 3& 1& a& b& a& \mathrm{\pi }& \sin \left(1\right)& \mathrm{undefined}& \mathrm{\infty }\end{array}\right]$

$\mathrm{RemoveNonNumeric}\left(A\right)$

$\left[\begin{array}{ccccc}3& 3& 1& \mathrm{\pi }& \sin \left(1\right)\end{array}\right]$

$\mathrm{SelectNonNumeric}\left(A\,\mathrm{exclude}=\left[\mathrm{undefined}\right]\right)$

$\left[\begin{array}{cccc}a& b& a& \mathrm{\infty }\end{array}\right]$

$\mathrm{RemoveNonNumeric}\left(A\,\mathrm{exclude}=\left[\mathrm{undefined}\right]\right)$

$\left[\begin{array}{cccccc}3& 3& 1& \mathrm{\pi }& \sin \left(1\right)& \mathrm{undefined}\end{array}\right]$

$\mathrm{SelectNonNumeric}\left(A\right)$

$\left[\begin{array}{ccccc}a& b& a& \mathrm{undefined}& \mathrm{\infty }\end{array}\right]$

$B≔\mathrm{Array}\left(\left[1\,2\,3\,4\,\mathrm{undefined}\,\mathrm{\infty }\right]\,\mathrm{datatype}=\mathrm{float}\left[8\right]\right)$

$B≔\left[\begin{array}{cccccc}1.& 2.& 3.& 4.& Float\left(\mathrm{undefined}\right)& Float\left(\mathrm{\infty }\right)\end{array}\right]$

$\mathrm{RemoveNonNumeric}\left(B\right)$

$\left[\begin{array}{cccc}1.& 2.& 3.& 4.\end{array}\right]$

$\mathrm{RemoveNonNumeric}\left(B\,\mathrm{exclude}=\left[\mathrm{\infty }\right]\right)$

$\left[\begin{array}{ccccc}1.& 2.& 3.& 4.& Float\left(\mathrm{\infty }\right)\end{array}\right]$