RUser_Jenny - 10 months ago 41

R Question

I have migration data that is row based.

`param <- c("A", "B", "C")`

df <- data.frame(Case1 = c("A", "A", "B", "B"),

Case2 = c("A", "C", "A", "B"),

Val = c(0.5,0.4,0.3,0.7))

So this data frame looks like

Case1 Case2 Val

1 A A 0.5

2 A C 0.4

3 B A 0.3

4 B B 0.7

This row based data frame should be transformend in an kind of "migration matrix".

`dd <- data.frame(cA = c(0.5, 0.3, 0),`

cB = c(0, 0.7, 0),

cC = c(0.4,0,0))

rownames(dd) <- paste0("Case1","_", param)

colnames(dd) <- paste0("Case2","_", param)

So the migration matrix looks like

Case2_A Case2_B Case2_C

Case1_A 0.5 0.0 0.4

Case1_B 0.3 0.7 0.0

Case1_C 0.0 0.0 0.0

Does anyone know a good way to do this in R? Thank you very much!

Answer Source

With base R:

```
df
Case1 Case2 Val
1 A A 0.5
2 A C 0.4
3 B A 0.3
4 B B 0.7
library(reshape2)
levels(df$Case1) <- c(levels(df$Case1), 'C')
df <- dcast(df, Case1~Case2, value.var='Val', drop=FALSE)
rownames(df) <- paste('Case1', df[,1], sep='_')
df <- df[-1]
names(df) <- paste('Case2', names(df), sep='_')
df[is.na(df)] <- 0.0
df
Case2_A Case2_B Case2_C
Case1_A 0.5 0.0 0.4
Case1_B 0.3 0.7 0.0
Case1_C 0.0 0.0 0.0
```