diff --git a/eval_chart.py b/eval_chart.py
new file mode 100644
index 0000000..a139371
--- /dev/null
+++ b/eval_chart.py
@@ -0,0 +1,45 @@
+import openpyxl
+import numpy as np
+import matplotlib.pyplot as plt
+
+
+def excel_range(filename, r):
+    wb = openpyxl.load_workbook(filename)
+    sheet = wb[wb.sheetnames[0]]
+    return [[cell.value for cell in sheet[r][i]] for i in range(len(sheet[r]))]
+
+
+led_sp = np.float32(excel_range("Spectrum.xlsx", "B2:AF2")[0])
+cmf_sp = np.float32(excel_range("Spectrum.xlsx", "B3:AF5"))
+filter_sp = np.float32(excel_range("Spectrum.xlsx", "B6:AF8"))
+tcc_sp = np.float32(excel_range("handy_tcc.xlsx", "F2:AJ25")) / 100
+# print("led=", led_sp)
+
+sum_y = led_sp.dot(cmf_sp[1])
+k = 100.0 / sum_y
+
+tcc_xyz = np.zeros((24, 3), np.float32)
+for patch_no in range(24):
+    tcc_xyz[patch_no, 0] = (led_sp * tcc_sp[patch_no]).dot(cmf_sp[0]) * k
+    tcc_xyz[patch_no, 1] = (led_sp * tcc_sp[patch_no]).dot(cmf_sp[1]) * k
+    tcc_xyz[patch_no, 2] = (led_sp * tcc_sp[patch_no]).dot(cmf_sp[2]) * k
+    # print(patch_no, tri_x, tri_y, tri_z, sep="\t")
+print("tcc_xyz=")
+print(tcc_xyz)
+
+white_patch = 0
+white_balance = np.float32([240, 240, 240])
+raw_rgb = np.float32(
+    [(led_sp * tcc_sp[white_patch]).dot(filter_sp[i]) for i in range(3)]
+)
+print("raw_rgb=", raw_rgb)
+rgb_gain = white_balance / raw_rgb
+print("rgb_gain=", rgb_gain)
+tcc_rgb = np.zeros((24, 3), np.float32)
+for patch_no in range(24):
+    tcc_rgb[patch_no, 0] = (led_sp * tcc_sp[patch_no]).dot(filter_sp[0]) * rgb_gain[0]
+    tcc_rgb[patch_no, 1] = (led_sp * tcc_sp[patch_no]).dot(filter_sp[1]) * rgb_gain[1]
+    tcc_rgb[patch_no, 2] = (led_sp * tcc_sp[patch_no]).dot(filter_sp[2]) * rgb_gain[2]
+    # print(patch_no, tri_x, tri_y, tri_z, sep="\t")
+print("tcc_rgb=")
+print(tcc_rgb)