Display a linear combination: Difference between revisions

<lang rexx>/*REXX program displays a finite liner combination in an infinite vector basis. */

@.= .; @.1 = ' 1, 2, 3 @.1 = ' 1, 2,/*define a 3specific test case for 'build*/

@.2 = ' 0, 1, 2, 3 ' @.2 =/* '" 0, " 1, 2, 3" ' " " " " */

@.3 = ' 1, 0, 3, 4 ' @.3 =/* '" 1, " 0, 3, 4" ' " " " " */

@.4 = ' 1, 2, 0 @.4' = /* ' 1," 2, " 0 " ' " " " " */

@.5 = ' 0, 0, 0 @.5' = /* ' 0," 0, " 0 " ' " " " " */

@.6 = 0 @.6 = 0 /* " " " " " " " */

@.7 = ' 1, 1, 1 @.7' = /* ' 1," 1, " 1 " ' " " " " */

@.8 = ' -1, -1, -1 ' @.8 /* = " ' -1, -1," -1 " ' " " " " */

@.9 = ' -1, -2, 0, -3 ' /* @.9 =" '" -1, -2, 0, -3" ' " " " " */

@.10 = -1 @.10 = -1 /* " " " " " " " */

do j=1 while @.j\==.; n= 0 n= 0 /*process each vector; zero element cnt*/

do k=1 for words(y); #= word(y, k) /* ◄───── process each of the elements.*/

if #=0 then iterate; a= abs(# / 1) /*if the value is zero, then ignore it.*/

if #<0 then s= '+- ' ; if #<0 then s= "- " /*define the sign: plus(+) or minus (-). */

n= n + 1; if n==1 thenelse s= strip(s)'+ ' /*if the 1st element" " " plus (+). used, remove blank*/

if a\=n= n + 1 then s= s || a'*' /*ifbump multiplierthe isnumber unity,of thenelements ignorein #vector*/

$ if n==1 $ then s'e= strip('k"s)" /*if the 1st element used, remove /*construct a liner combination elementblank*/