# I want to plot the Roc curve using perfcurve function i have 2 plot which code is right

2 ビュー (過去 30 日間)
Salma Hassan 2018 年 7 月 27 日
コメント済み: KALYAN ACHARJYA 2018 年 7 月 30 日
the code is [Xpr,Ypr,Tpr,AUCpr] = perfcurve(targets,abs(scores(:,1)), 1, 'xCrit', 'reca', 'yCrit', 'fpr');
plot(Xpr,Ypr)
xlabel('specificity'); ylabel('sensitivity') title(['ROC curve (AUC: ' num2str(AUCpr) ')'])
where scores(2 columns ) the first for predict abnormal image and the second for normal the problem is i got this graph
and if i change the score into abs(scores(:,2)), 1,i get an extremely different graph

サインインしてコメントする。

### 採用された回答

KALYAN ACHARJYA 2018 年 7 月 29 日

Let me clear that ROC curve: 1-specificity vs sensitivity (In your figure x-axis is specificity). Ant the traditional ROC curve looks like as second figure. First one is incorrect. If your curve position towards the northwest corner, it is more accurate. Better follow TOM paper , here explains everything.
Attache figure for some sample ROC curves. AUC value range from 0.5-0.99,AUC value in larger side more better the proposed method. Curve never appper below the reference line (In attached figure red line).Purple curve having better method.
Cheers!
##### 2 件のコメントなしを表示なしを非表示
Salma Hassan 2018 年 7 月 30 日
thanks so much what does the red line represent ? [Xpr,Ypr,Tpr,AUCpr] = perfcurve(....
KALYAN ACHARJYA 2018 年 7 月 30 日
Just reference line, worst condition (50% random probability ), your ROC curve on that line.

サインインしてコメントする。

### カテゴリ

Help Center および File ExchangeROC - AUC についてさらに検索

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by