update readme

README.md

@@ -170,5 +170,5 @@ The Receiver Operating Characteristic (ROC) curve is a valuable tool for assessi
 
 
 <div id="bg"  align="center">
-  <img src="./vignettes/figs/evaluation.png" width="340" height="200">
+  <img src="./vignettes/figs/evaluation.png" width="680" height="400">
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