摘要
目的 探索ROC曲线下面积Az值与ND轴坐标系下截距a的关系。方法 假设信号 (signal,S)与噪声(noise,N)服从同一方差的正态分布 ,使用积分中的换元法求出Az值与截距的关系式 ,并编程由a计算出Az值。结果 Az值介于 0 5到 1之间 ,随a的增大而增加。结论 Az值与a之间有内在的关系 ,均可反映诊断水平的高低。
Objective: To study relationship between the area under the curve (Az) and intercept (a). Methods: Suppose the signal and noise were gaussian distributions with the same variance, a formula was deduced and Az was calculated with the intercept. Results: The Az ranged from 0.5 to 1 and increased with intercept accretion. Conclusion: Az and intercept have intrinsic relation, which reflects the level of diagnosis.
出处
《泰山医学院学报》
CAS
2003年第2期102-105,共4页
Journal of Taishan Medical College
关键词
ROC曲线
信号
噪声
正态分布
ROC曲线下的面积(Az)
截距
receiver operating characteristic (ROC) curve
signal
noise
normal distribution
the area under the ROC curve(Az)
intercept
