finished cleaning up elementwise univariate and affine atoms

Author: dance858

README.md

@@ -1,7 +1,5 @@
-1. power should be double
-2. can we reuse calculations, like in hessian of logistic
 3. more tests for chain rule elementwise univariate hessian
 4. in the refactor, add consts
 5. multiply with one constant vector/scalar argument
 6. AX where X is a matrix. Can that happen? How is that canonicalized? Maybe it can't happen.
-7. Must be able to compute jacobian and hessian of A @ phi(x), so linear operator needs other code?
+7. Must be able to compute jacobian and hessian of A @ phi(x), so linear operator needs other code! This requires new infrastructure, I think.

include/elementwise_univariate.h

@@ -18,7 +18,7 @@ expr *new_tanh(expr *child);
 expr *new_asinh(expr *child);
 expr *new_atanh(expr *child);
 expr *new_logistic(expr *child);
-expr *new_power(expr *child, int p);
+expr *new_power(expr *child, double p);
 expr *new_xexp(expr *child);
 
 /* the jacobian and wsum_hess for elementwise univariate atoms are always

include/subexpr.h

@@ -22,7 +22,7 @@ typedef struct linear_op_expr
 typedef struct power_expr
 {
     expr base;
-    int p;
+    double p;
 } power_expr;
 
 /* Quadratic form: y = x'*Q*x */

src/elementwise_univariate/power.c

@@ -40,7 +40,7 @@ static void local_wsum_hess(expr *node, double *out, const double *w)
     }
 }
 
-expr *new_power(expr *child, int p)
+expr *new_power(expr *child, double p)
 {
     /* Allocate the type-specific struct */
     power_expr *pnode = (power_expr *) calloc(1, sizeof(power_expr));

src/other/quad_form.c

@@ -5,13 +5,11 @@
 #include <math.h>
 #include <stdlib.h>
 
-/* Note: Q is not freed here because it's owned by the caller */
-
 static void forward(expr *node, const double *u)
 {
     expr *x = node->left;
 
-    /* children's forward passes */
+    /* child's forward pass */
     x->forward(x, u);
 
     /* local forward pass  */
@@ -45,8 +43,7 @@ static void jacobian_init(expr *node)
     else /* x is not a variable */
     {
         /* compute required allocation and allocate jacobian */
-        bool *col_nz = (bool *) calloc(
-            node->n_vars, sizeof(bool)); /* TODO: could use iwork here instead*/
+        bool *col_nz = (bool *) calloc(node->n_vars, sizeof(bool));
         int nonzero_cols = count_nonzero_cols(x->jacobian, col_nz);
         node->jacobian = new_csr_matrix(1, node->n_vars, nonzero_cols + 1);
 
@@ -65,9 +62,6 @@ static void jacobian_init(expr *node)
 
         node->jacobian->p[0] = 0;
         node->jacobian->p[1] = node->jacobian->nnz;
-
-        /* Cast x to linear operator to use its A_csc in eval_jacobian */
-        node->iwork = (int *) malloc(sizeof(int));
     }
 }
 
@@ -109,6 +103,7 @@ expr *new_quad_form(expr *left, CSR_Matrix *Q)
     expr *node = &qnode->base;
 
     /* Initialize base fields */
+    assert(left->d2 == 1);
     init_expr(node, left->d1, 1, left->n_vars, forward, jacobian_init, eval_jacobian,
               NULL, NULL);
 

tests/wsum_hess/test_power.h

@@ -15,7 +15,7 @@ const char *test_wsum_hess_power()
     double w[3] = {1.0, 2.0, 3.0};
 
     expr *x = new_variable(3, 1, 0, 3);
-    expr *power_node = new_power(x, 3);
+    expr *power_node = new_power(x, 3.0);
     power_node->forward(power_node, u_vals);
     power_node->wsum_hess_init(power_node);
     power_node->eval_wsum_hess(power_node, w);