Polyval handles non-array as second argument (#601)

* Factorize polynomial evaluation

* Polyval handles non-array as second argument

---------

Co-authored-by: Zoltán Vörös <[email protected]>

Author: HugoNumworks

code/numpy/poly.c

@@ -145,9 +145,18 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(poly_polyfit_obj, 2, 3, poly_polyfit);
 
 #if ULAB_NUMPY_HAS_POLYVAL
 
+static mp_float_t poly_eval(mp_float_t x, mp_float_t *p, uint8_t plen) {
+    mp_float_t y = p[0];
+    for(uint8_t j=0; j < plen-1; j++) {
+        y *= x;
+        y += p[j+1];
+    }
+    return y;
+}
+
 mp_obj_t poly_polyval(mp_obj_t o_p, mp_obj_t o_x) {
-    if(!ndarray_object_is_array_like(o_p) || !ndarray_object_is_array_like(o_x)) {
-        mp_raise_TypeError(translate("inputs are not iterable"));
+    if(!ndarray_object_is_array_like(o_p)) {
+        mp_raise_TypeError(translate("input is not iterable"));
     }
     #if ULAB_SUPPORTS_COMPLEX
     ndarray_obj_t *input;
@@ -171,6 +180,10 @@ mp_obj_t poly_polyval(mp_obj_t o_p, mp_obj_t o_x) {
         i++;
     }
 
+    if(!ndarray_object_is_array_like(o_x)) {
+        return mp_obj_new_float(poly_eval(mp_obj_get_float(o_x), p, plen));
+    }
+
     // polynomials are going to be of type float, except, when both
     // the coefficients and the independent variable are integers
     ndarray_obj_t *ndarray;
@@ -198,13 +211,7 @@ mp_obj_t poly_polyval(mp_obj_t o_p, mp_obj_t o_x) {
                 #endif
                     size_t l = 0;
                     do {
-                        mp_float_t y = p[0];
-                        mp_float_t _x = func(sarray);
-                        for(uint8_t m=0; m < plen-1; m++) {
-                            y *= _x;
-                            y += p[m+1];
-                        }
-                        *array++ = y;
+                        *array++ = poly_eval(func(sarray), p, plen);
                         sarray += source->strides[ULAB_MAX_DIMS - 1];
                         l++;
                     } while(l < source->shape[ULAB_MAX_DIMS - 1]);
@@ -233,13 +240,7 @@ mp_obj_t poly_polyval(mp_obj_t o_p, mp_obj_t o_x) {
         mp_obj_iter_buf_t x_buf;
         mp_obj_t x_item, x_iterable = mp_getiter(o_x, &x_buf);
         while ((x_item = mp_iternext(x_iterable)) != MP_OBJ_STOP_ITERATION) {
-            mp_float_t _x = mp_obj_get_float(x_item);
-            mp_float_t y = p[0];
-            for(uint8_t j=0; j < plen-1; j++) {
-                y *= _x;
-                y += p[j+1];
-            }
-            *array++ = y;
+            *array++ = poly_eval(mp_obj_get_float(x_item), p, plen);
         }
     }
     m_del(mp_float_t, p, plen);

code/ulab.c

@@ -33,7 +33,7 @@
 #include "user/user.h"
 #include "utils/utils.h"
 
-#define ULAB_VERSION 6.3.2
+#define ULAB_VERSION 6.3.3
 #define xstr(s) str(s)
 #define str(s) #s