NCL Website header
NCL Home > Documentation > Functions > Type converters

tochar

Converts values of any snumeric data type or string to values of type char.

Available in version 5.2.0 and later.

Prototype

	function tochar (
		input_val  : snumeric data type or string   
	)

	return_val [dimsizes(input_val)] :  char

Arguments

input_val

A variable of any snumeric data type or string of any dimension.

Return value

Returns characters. If the input variable is float or double, then any fractional part of the input values is truncated. The dimensionality of the output matches that of the input.

Any input value that is out of range for a character will be returned as a missing value.

Description

This function converts any snumeric data or string to character values. If the input is float or double, then the fractional part is truncated.

Any input value that is out of range for a character will be returned as a missing value.

Attributes, with the exception of _FillValue, are not propagated by the conversion functions.

Special considerations apply to how missing values and out-of-range values are handled in the conversion functions. For this function, an out-of-range value could be valid in its original type, but not in the valid range of a character. An out-of-range value is converted to a missing value, but what that missing value is depends on the circumstances of the particular conversion being performed. For example, determination has to be made whether a missing value for a variable to be converted is in the range of the type of the target variable.

Important notes:

  • When converting a string to character array using tochar, there is no ending NULL character (appears as '\0' in C program language) at the end of the array.

  • When converting a string to character array using stringtocharacter, there is an ending NULL character at the end of the array.

  • In NCL versions 6.1.0 and earlier, tochar was including the NULL character. This was considered a bug and was fixed in version 6.1.2.

  • The NCL developers generally recommend using tochar to convert strings to character arrays.

See Also

tobyte, toshort, toushort, toint, touint, toint64, touint64, tostring, totype

Examples

Example 1

Converting short to character:

 short_array = (/ (/5h, 200h/), (/0h, -100h/) /)
 short2char = tochar(short_array)
 print(short2char)
Output:
warning:There are 1 int less than 0, which has been flagged missing.
. . .
  _FillValue :  0x00
(0,0)   0x05
(0,1)   0xc8
(1,0)   0x00
(1,1)   0x00
Example 2

Converting unsigned short to character:

 ushort_array = (/(/800H, 24464H/), (/1H, 24465H/)/)
 ushort2char = tochar(ushort_array)
 print(ushort2char)
Output:

warning:There are 3 int larger than UCHAR_MAX, which has been flagged missing.
. . .
Number Of Attributes: 1
  _FillValue :  0x00
(0,0)   0x00
(0,1)   0x00
(1,0)   0x01
(1,1)   0x00
Example 3

Converting integer to character:

 int_array = (/(/2147483640,10/), (/3,0/)/)
 int2char = tochar(int_array)
 print(int2char)
Output:

warning:There are 1 int larger than UCHAR_MAX, which has been flagged missing.
. . .
  _FillValue :  0x00
(0,0)   0x00
(0,1)   

(1,0)   0x03
(1,1)   0x00
Example 4

Converting unsigned integer to character:

 uint_array = (/ (/2147483649I,1I/),(/50I,2I/)/)
 uint2char = tochar(uint_array)
 print(uint2char)
Output:

warning:There are 1 unsigned int larger than UCHAR_MAX, which has been flagged missing.
. . .
  _FillValue :  0x00
(0,0)   0x00
(0,1)   0x01
(1,0)   2
(1,1)   0x02
Example 5

Converting numbers in strings to character:

 str_array = (/ (/"3","0"/), (/"64","99999"/)/)
 str2char = tochar(str_array)
 print(str2char)
Output:

Variable: str2char
Type: character
Total Size: 20 bytes
            20 values
Number of Dimensions: 3
Dimensions and sizes:   [2] x [2] x [5]
Coordinates: 
(0,0,0) 3
(0,0,1) 0x00
(0,0,2) 0x00
(0,0,3) 0x00
(0,0,4) 0x00
(0,1,0) 0
(0,1,1) 0x00
(0,1,2) 0x00
(0,1,3) 0x00
(0,1,4) 0x00
(1,0,0) 6
(1,0,1) 4
(1,0,2) 0x00
(1,0,3) 0x00
(1,0,4) 0x00
(1,1,0) 9
(1,1,1) 9
(1,1,2) 9
(1,1,3) 9
(1,1,4) 9