# Recent content by CedricLVQ

1. ### P charts based on binomial distribution - Statistical Process Control

Thank you Miner for all these valuable informations. I didn't know the existence of such forums, there are gonna help me in the future for sure. Your comments and the interview of David Laney about the misuse of p-charts confirmed my fear about the use of p-charts even if I was more concerned...
2. ### P charts based on binomial distribution - Statistical Process Control

Hello all, I have a question related to the use of p-chart in a process where there are defect rates measured. The control limits for this type of chart is calculated with +/- 3 sigmas around the mean (with mean = np and sd = sqrt(n*(1-p)*p)) As it is using i +/- 3 sigmas it assumes that we...
3. ### Include supplementary individuals PCA with PROC PRINCOMP

Yes that's it. The individuals used for model estimation will be the "reference period" and determine the eigenvectors of the PCA model. Then the ellipse on individuals (i.e 95% or 99.73% as in control charts approach) will the referential for outliers detection for the next individuals that are...
4. ### Include supplementary individuals PCA with PROC PRINCOMP

Supplementary means that they are not taken into account in the correlation matrix used for decomposition of eigen vectors. Then they are plotted and scored using these eigen vectors. Here is an example with R code: res.pca <- PCA(decathlon2, ind.sup = 24:27, quanti.sup =...
5. ### Include supplementary individuals PCA with PROC PRINCOMP

Hello, I am using PCA with PROC PRINCOMP to perform multivariate statistical process control and would like to build a PCA only on a certain set of individuals and let the others as supplementary. Anyone knows how to do it? I know this functionality exists with other software such as R...
6. ### Interpret Linear Discriminant Analysis and visualization

Hello, I performed a LDA in R but I'm a bit concerned about how I could present my results. I didn't do any scaling before the data analysis, is it recommended to do so? When I do the LDA, I got the following coefficients: Coefficients of linear discriminants: LD1 CHP -8.7908674 CD...
7. ### Design of experiments across the time

I have 900 unique units. As the test to measure Y is destructive, at each timepoint 180 units are tested (30 for each combination). That's why I am wondering if using REPEATED statement is allowed in this case. Anyway I will get to PROC MIXED and keep you informed. Sorry @Miner these data...
8. ### Compute prediction intervals in Random Forest Regression

Hello, I am trying to use Random Forest Regression to better predict the output of a manufacturing process. Until now, I was using PLS regression to do so but it turned out that Random Forest Regression gave better results (lower RMSE on the test dataset). My main concern is that I am not able...
9. ### Hello statisticians and data enthusiasts!

Hello everyone, I just joined the forum and posted my first message some minutes ago. I am statistician working in a pharmaceutical industrial sites and thus apply statistics to industrial field. I hope we could share some of the statistics that are used in Industry such as Statistical Process...
10. ### Design of experiments across the time

Hi all, I am trying to model a continous variable across the time with several timepoints (0,3,6,9 and 12 months) and 2 predictors. One is continuous (5 and 10) and the other is categorical (A, B and C) and for each of the combinaison I have 30 replicates. The relation between Y and the...