Deploying to stdlib-fpm from @ fba31e0 🚀

Author: milancurcic

example/example_cross_product.f90

@@ -0,0 +1,9 @@
+program demo_cross_product
+    use stdlib_linalg, only: cross_product
+    implicit none
+    real :: a(3), b(3), c(3)
+    a = [1., 0., 0.]
+    b = [0., 1., 0.]
+    c = cross_product(a, b)
+    !c = [0., 0., 1.]
+end program demo_cross_product

src/stdlib_linalg.f90

@@ -12,6 +12,7 @@ module stdlib_linalg
   public :: eye
   public :: trace
   public :: outer_product
+  public :: cross_product
   public :: is_square
   public :: is_diagonal
   public :: is_symmetric
@@ -240,6 +241,47 @@ end function outer_product_iint64
   end interface outer_product
 
 
+  ! Cross product (of two vectors)
+  interface cross_product
+    !! version: experimental
+    !!
+    !! Computes the cross product of two vectors, returning a rank-1 and size-3 array
+    !! ([Specification](../page/specs/stdlib_linalg.html#cross_product-computes-the-cross-product-of-two-3-d-vectors))
+      pure module function cross_product_rsp(a, b) result(res)
+        real(sp), intent(in) :: a(3), b(3)
+        real(sp) :: res(3)
+      end function cross_product_rsp
+      pure module function cross_product_rdp(a, b) result(res)
+        real(dp), intent(in) :: a(3), b(3)
+        real(dp) :: res(3)
+      end function cross_product_rdp
+      pure module function cross_product_csp(a, b) result(res)
+        complex(sp), intent(in) :: a(3), b(3)
+        complex(sp) :: res(3)
+      end function cross_product_csp
+      pure module function cross_product_cdp(a, b) result(res)
+        complex(dp), intent(in) :: a(3), b(3)
+        complex(dp) :: res(3)
+      end function cross_product_cdp
+      pure module function cross_product_iint8(a, b) result(res)
+        integer(int8), intent(in) :: a(3), b(3)
+        integer(int8) :: res(3)
+      end function cross_product_iint8
+      pure module function cross_product_iint16(a, b) result(res)
+        integer(int16), intent(in) :: a(3), b(3)
+        integer(int16) :: res(3)
+      end function cross_product_iint16
+      pure module function cross_product_iint32(a, b) result(res)
+        integer(int32), intent(in) :: a(3), b(3)
+        integer(int32) :: res(3)
+      end function cross_product_iint32
+      pure module function cross_product_iint64(a, b) result(res)
+        integer(int64), intent(in) :: a(3), b(3)
+        integer(int64) :: res(3)
+      end function cross_product_iint64
+  end interface cross_product
+
+
   ! Check for squareness
   interface is_square
     !! version: experimental

src/stdlib_linalg_cross_product.f90

@@ -0,0 +1,80 @@
+submodule (stdlib_linalg) stdlib_linalg_cross_product
+
+    implicit none
+
+contains
+
+    pure module function cross_product_rsp(a, b) result(res)
+        real(sp), intent(in) :: a(3), b(3)
+        real(sp) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_rsp
+    pure module function cross_product_rdp(a, b) result(res)
+        real(dp), intent(in) :: a(3), b(3)
+        real(dp) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_rdp
+    pure module function cross_product_csp(a, b) result(res)
+        complex(sp), intent(in) :: a(3), b(3)
+        complex(sp) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_csp
+    pure module function cross_product_cdp(a, b) result(res)
+        complex(dp), intent(in) :: a(3), b(3)
+        complex(dp) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_cdp
+    pure module function cross_product_iint8(a, b) result(res)
+        integer(int8), intent(in) :: a(3), b(3)
+        integer(int8) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_iint8
+    pure module function cross_product_iint16(a, b) result(res)
+        integer(int16), intent(in) :: a(3), b(3)
+        integer(int16) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_iint16
+    pure module function cross_product_iint32(a, b) result(res)
+        integer(int32), intent(in) :: a(3), b(3)
+        integer(int32) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_iint32
+    pure module function cross_product_iint64(a, b) result(res)
+        integer(int64), intent(in) :: a(3), b(3)
+        integer(int64) :: res(3)
+
+        res(1) = a(2) * b(3) - a(3) * b(2)
+        res(2) = a(3) * b(1) - a(1) * b(3)
+        res(3) = a(1) * b(2) - a(2) * b(1)
+
+    end function cross_product_iint64
+
+end submodule