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I guess if you want a library for linear algebra operations in Lisp, you just write them yourself. From McCarthy's collection: ;;; multiplying a matrix by a co

I guess if you want a library for linear algebra operations in Lisp, you just write them yourself. From McCarthy's collection: ;;; multiplying a matrix by a column vector (defun mvmult (matrix vector) (list (scap (nth 0 matrix) vector) (scap (nth 1 matrix) vector))) ;;; sum of two vectors (defun vplus (vec1 vec2) (list (+ (nth 0 vec1) (nth 0 vec2)) (+ (nth 1 vec1) (nth 1 vec2)))) ;;; difference of two vectors (defun vminus (vec1 vec2) (list (- (nth 0 vec1) (nth 0 vec2)) (- (nth 1 vec1) (nth 1 vec2)))) ;;; scalar product of two vectors (defun scap (vec1 vec2) (+ (* (nth 0 vec1) (nth 0 vec2)) (* (nth 1 vec1) (nth 1 vec2)))) ;;; product of scalar and vector (defun svmult (sca vec) (list (* sca (nth 0 vec)) (* sca (nth 1 vec)))) ;;; sum of a list of vectors (defun addup (veclist) (if (null veclist) zerovec (vplus (car veclist) (addup (cdr veclist))))) (defconst zerovec '(0 0) "zero vector with two components"1) ;;; length of a vector (defun length (x) (sqrt (+ (expt (nth 0 x) 2) (expt (nth 1 x) 2)))) (defconst Imatrix '((1.0 0.0) (0.0 1.0)) "unit 2x2 matrix") (defun smmult (sca matrix) (list (svmult sca (nth 0 matrix)) (svmult sca (nth 1 matrix)))) (defun mplus (mat1 mat2) (list (vplus (nth 0 mat1) (nth 0 mat2)) (vplus (nth 1 mat1) (nth 1 mat2)))) (defun mminus (mat1 mat2) (list (vminus (nth 0 mat1) (nth 0 mat2)) (vminus (nth 1 mat1) (nth 1 mat2)))) (defun mmult (mat1 mat2) (list (list (scap (nth 0 mat1) (col 0 mat1)) (scap (nth 0 mat1) (col 1 mat1))) (list (scap (nth 1 mat1) (col 0 mat1)) (scap (nth 1 mat1) (col 1 mat1))))) (defun multiplyup (matlist) (if (null matlist) Imatrix (mmult (car matlist) (multiplyup (car matlist) (multiplyup (cdr (matlist)))))))

BaculumMeumEst 3y ago
see also https://github.com/jb55/vrscript-samples/blob/master/vr.rkt https://github.com/jb55/vrscript-samples/blob/master/vr.rkt
zelphirkalt 3y ago
Of course one can do this and it might work as a stopgap solution and abstraction layer until something different comes along and I have done similar, but ultimately this will not be very efficient. It might be a better, albeit less beautiful, solution to use any low level language inplemented linear algebra bindings for the lisp at hand. Hopefully there existing one.

BaculumMeumEst 3y ago

see also https://github.com/jb55/vrscript-samples/blob/master/vr.rkt https://github.com/jb55/vrscript-samples/blob/master/vr.rkt

zelphirkalt 3y ago

Of course one can do this and it might work as a stopgap solution and abstraction layer until something different comes along and I have done similar, but ultimately this will not be very efficient. It might be a better, albeit less beautiful, solution to use any low level language inplemented linear algebra bindings for the lisp at hand. Hopefully there existing one.