\ 5 point Gauss-Laguerre integration MARKER -gauss needs ftran111.f 12.640800844276e0 FVARIABLE x4 x4 F! 7.085810005859e0 FVARIABLE x3 x3 F! 3.596425771041e0 FVARIABLE x2 x2 F! 1.413403059107e0 FVARIABLE x1 x1 F! 0.263560319718e0 FVARIABLE x0 x0 F! 5.21755610583e-1 FVARIABLE w0 w0 F! 3.98666811083e-1 FVARIABLE w1 w1 F! 7.59424496817e-2 FVARIABLE w2 w2 F! 3.61175867992e-3 FVARIABLE w3 w3 F! 2.33699723858e-5 FVARIABLE w4 w4 F! v: fdummy : )int ( f: a b -- integral) ( xt --) defines fdummy f" w0 * fdummy(x0) + w1 * fdummy(x1) + w2* fdummy(x2) + w3 * fdummy(x3) + w4 * fdummy(x4) " ; FALSE [IF] Examples: 10 set-precision use( fcos )int f. .5005384852 ok \ exact = 0.5 : f1 f2* fcos ; \ cos(2x) use( f1 )int f. .1183827839 ok \ exact = 0.2 use( fsin )int f. .4989033210 ok \ exact = 0.5 : f2 f2* fsin ; ok \ sin(2x) use( f2 )int f. .4494545483 ok \ exact = 0.4 : f3 fdup f^4 f* fdup 2e0 f- f* 1e0 f+ ; \ x^10 - 2x^5 + 1 use( f3 )int f. 3614161.000 ok \ exact = 3628561 : f4 f^4 fdup 2e0 f- f* 1e0 f+ ; ok \ x^8 - 2x^4 + 1 1e0 f4 f. .0000000000 ok 2e0 f4 f. 225.0000000 ok use( f4 )int f. 40273.00000 ok \ exact = 40273 [THEN]