# ratio

## ratio相关知识

• Risk Ratio 和 Odds Ratio
Data Science Day 15 Risk Ratio Last time, we give a SAS example of Risk Difference to test if two groups are experiencing the same proportion of a certain event. In order to understand the topic better, we will go over Risk Ratio. Definition: Risk Ratio or Relative Risk (RR) is the probability that an event occurs in a group 1 relative to the probability that the same event occurs in gr
• Odds Ratio
Data Science Day 12:&nbsp;Odds RatioLearning Objective:&nbsp;Probability vs Odds Vs Odds Ratio1. Probability = Event/Sample Space2. Odds= Prob(Event)/Prob(Non-Event)3. Odds Ratio = Odds(Group 1)/ Odds(Group 2)InterpretationThe Odds Ratio is a measure of association between exposure and outcome.OR=Odds(Group 1)/Odds(Group2)&gt;1&nbsp;indicates the increased occurrence of an event in Group 1 compared to Group 2.OR=Odds(Group 1)/Odds(Group2) &lt; 1&nbsp;indic
• canvas 显示模糊问题
//=== canvas 模糊问题 start var ratio = getPixelRatio(ct); if(ratio == 1) { // PC端 PixelRatio ratio = 2; } cs.style.width = cs.width + &#039;px&#039;; cs.style.height = cs.height + &#039;px&#039;; cs.width = cs.width * ratio; cs.height = cs.height * ratio; ct.scale(ratio, ratio); //=== canvas 模糊问题 end var getPixelRatio = function (context) { var backingStore = context.backingStorePixelRatio || context.webkitBackingS
• proc phreg
SAS day 17: Proc PhregOne day, my boss took a glance at a table with Hazard Ratio and Median Survival Time then he told me the program set the reference group in Proc Phreg wrong.It turns out he was correct after validating the program. However, I was very curious about how did he figure it out by an Augenblick. Then he shared with us some knowledge about Hazard Ratio and Proc Phreg.Background knowledgeHazard Ratio: HRs represent instantaneous risk over th