;+ ; :NAME: ; DOT_PRODUCT ; ; :PURPOSE: ; This function will compute the dot product between two provided vectors ; (or arrays or vectors) in n-space. ; ; :CATEGORY: ; General. ; ; :CALLING SEQUENCE: ; Result = DOT_PRODUCT( vector1, vector2 ) ; ; :INPUTS: ; vector1 ; A n-dimensional vector -OR- an array of N n-dimensional vectors (nxN) ; vector2 ; A n-dimensional vector -OR- an array of N n-dimensional vectors (nxN) ; (NOTE: The provided vector dimensions and number of vectors must be equal) ; ; :KEYWORD PARAMETERS: ; None ; ; :RESULT: ; A scalar or a vector containg the dot product(s) between the provided ; vectors. ; ; :SIDE EFFECTS: ; If the size of the provided vectors do not match, execution will be halted ; and a session reset will occur. ; ; :REQUIRES: ; ARRAYS_ARE_SAME_SIZE ; ; :MODIFICATION HISTORY: ; Written by: Carl Salvaggio ; September, 2009 Original code ; ; :DISCLAIMER: ; This source code is provided "as is" and without warranties as to performance ; or merchantability. The author and/or distributors of this source code may ; have made statements about this source code. Any such statements do not ; constitute warranties and shall not be relied on by the user in deciding ; whether to use this source code. ; ; This source code is provided without any express or implied warranties ; whatsoever. Because of the diversity of conditions and hardware under which ; this source code may be used, no warranty of fitness for a particular purpose ; is offered. The user is advised to test the source code thoroughly before ; relying on it. The user must assume the entire risk of using the source code. ;- FUNCTION DOT_PRODUCT, vector1, vector2 ;+ ; Check if the dimension and the number of vectors are the same for both provided ; arguments ;- IF NOT ARRAYS_ARE_SAME_SIZE( vector1, vector2 ) THEN BEGIN MESSAGE, "Incompatible vector/array dimensions.", /CONTINUE HELP, vector1 HELP, vector2 RETALL ENDIF ;+ ; Create double-precision local copies of the provided vector(s) for use in the ; computation of the dot product ;- v1 = DOUBLE( vector1 ) v2 = DOUBLE( vector2 ) ;+ ; Return the dot product(s) between the provided vector(s) ;- RETURN, TOTAL( v1 * v2, 1 ) END