3  * SPDX-License-Identifier: Apache-2.0
12  * Floating-point contraction merges an operation of the form (a*b + c) from
32 	zassert_equal(y_axis[0], linear_interpolate(x_axis, y_axis, len, -1));  in ZTEST()
34 	zassert_equal(y_axis[0], linear_interpolate(x_axis, y_axis, len, x_axis[0] - 1));  in ZTEST()
50 	for (int i = 0; i < ARRAY_SIZE(x_axis); i++) {  in ZTEST()  local
51 		zassert_equal(y_axis[i], linear_interpolate(x_axis, y_axis, len, x_axis[i]));  in ZTEST()
63 	/* 0 to 4 -> 0 */  in ZTEST()
64 	for (int i = 0; i < 5; i++) {  in ZTEST()  local
65 		zassert_equal(0, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
67 	/* 5 to 14 -> 1 */  in ZTEST()
68 	for (int i = 5; i < 15; i++) {  in ZTEST()  local
69 		zassert_equal(1, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
71 	/* 15 to N -> 2 */  in ZTEST()
72 	for (int i = 15; i <= 20; i++) {  in ZTEST()  local
73 		zassert_equal(2, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
86 	/* y = (x - 2000) / 10 */  in ZTEST()
87 	for (int i = x_axis[0]; i <= x_axis[1]; i++) {  in ZTEST()  local
88 		expected = round((i - 2000.0) / 10.0);  in ZTEST()
89 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
95 	int32_t y_axis[] = {-100, -90, -80, -70, -60, -50, -40, -30, -20, -10, 0};  in ZTEST()
102 	/* y = ((x - 2000) / 10) - 100 */  in ZTEST()
103 	for (int i = x_axis[0]; i <= x_axis[len - 1]; i++) {  in ZTEST()  local
104 		expected = round((i - 2000.0) / 10.0 - 100.0);  in ZTEST()
105 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
112 	int32_t x_axis[] = {-3000, -2900, -2800, -2700, -2600, -2500,  in ZTEST()
113 			    -2400, -2300, -2200, -2100, -2000};  in ZTEST()
120 	for (int i = x_axis[0]; i <= x_axis[len - 1]; i++) {  in ZTEST()  local
121 		expected = round((i + 3000.0) / 10.0);  in ZTEST()
122 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
128 	int32_t y_axis[] = {-100, -90, -80, -70, -60, -50, -40, -30, -20, -10, 0};  in ZTEST()
129 	int32_t x_axis[] = {-3000, -2900, -2800, -2700, -2600, -2500,  in ZTEST()
130 			    -2400, -2300, -2200, -2100, -2000};  in ZTEST()
136 	/* y = ((x + 3000) / 10) - 100 */  in ZTEST()
137 	for (int i = x_axis[0]; i <= x_axis[len - 1]; i++) {  in ZTEST()  local
138 		expected = round((i + 3000.0) / 10.0 - 100.0);  in ZTEST()
139 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
152 	/* First line segment, y = 0.4x - 30 */  in ZTEST()
153 	for (int i = x_axis[0]; i <= x_axis[1]; i++) {  in ZTEST()  local
154 		expected = round(0.4 * i - 30.0);  in ZTEST()
155 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
158 	/* Second line segment, y = 1.6x - 210 */  in ZTEST()
159 	for (int i = x_axis[1]; i <= x_axis[2]; i++) {  in ZTEST()  local
160 		expected = round(1.6 * i - 210.0);  in ZTEST()
161 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
164 	/* Third line segment, y = 390 - 1.4x */  in ZTEST()
165 	for (int i = x_axis[2]; i <= x_axis[3]; i++) {  in ZTEST()  local
166 		expected = round(390.0 - 1.4 * i);  in ZTEST()
167 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()
170 	/* Fourth line segment, y = 240 - 0.8x */  in ZTEST()
171 	for (int i = x_axis[3]; i <= x_axis[4]; i++) {  in ZTEST()  local
172 		expected = round(240.0 - 0.8 * i);  in ZTEST()
173 		zassert_equal(expected, linear_interpolate(x_axis, y_axis, len, i));  in ZTEST()