isnum

Arguments

str

a character string or a matrix of character strings.

res

a boolean matrix.

Description

res = isnum(str) returns %t if str represents a number.

isnum does not handle "operations", but only pure scalar numbers. For instance, isnum("1+2*3") will return %f. Complex numbers are not concerned, because one complex number is defined by the addition of two parts.

Examples

isnum(['1'   , ..
    '-1.23'  , ..
    '+1e+23' , ..
    '1d+23'  , ..
    'A'      , ..
    '%e'     , ..
    '%pi'    , ..
    '%nan'   , ..
    'Nan'    , ..
    '%inf'   , ..
    'Inf'    , ..
    '1+%i*2' , ..
    '%eps-%eps*%i', ..
    '%inf+Nan*%i' ])

See Also

• isletter — check that characters of a string are alphabetic letters
• isdigit — check that characters of a string are digits between 0 and 9
• isalphanum — check that characters of a string are alphanumerics
• evstr — evaluation of expressions