R: ggplot: ¿Cómo se traza una matriz cuadrada (no simétrica) como un mapa de calor?

Question

La matriz cuadrada inicial tiene el siguiente aspecto:

 [,1]  [,2]  [,3]  [,4]  [,5]  [,6] 
[1,] 0.00000000 -0.03071266 -0.05202358 -0.06372259 -0.07458787 -0.09827112 
[2,] 0.03071266 0.00000000 -0.02131092 -0.03300993 -0.04387521 -0.06755846 
[3,] 0.05202358 0.02131092 0.00000000 -0.01169902 -0.02256430 -0.04624754 
[4,] 0.06372259 0.03300993 0.01169902 0.00000000 -0.01086528 -0.03454853 
[5,] 0.07458787 0.04387521 0.02256430 0.01086528 0.00000000 -0.02368325 
[6,] 0.09827112 0.06755846 0.04624754 0.03454853 0.02368325 0.00000000 
[7,] 0.13357242 0.10285976 0.08154884 0.06984982 0.05898454 0.03530130 
[8,] 0.16375877 0.13304611 0.11173519 0.10003618 0.08917089 0.06548765 
     [,7]  [,8] 
[1,] -0.13357242 -0.16375877 
[2,] -0.10285976 -0.13304611 
[3,] -0.08154884 -0.11173519 
[4,] -0.06984982 -0.10003618 
[5,] -0.05898454 -0.08917089 
[6,] -0.03530130 -0.06548765 
[7,] 0.00000000 -0.03018635 
[8,] 0.03018635 0.00000000 

puedo crear mapa de calor de esta manera:

heatmap(impl_spread,symm=TRUE) 

Pero me gustaría introducir valores en la parte superior de esta.

Si convierto esto trama de datos (para usar ggplot), que se parece a esto como se esperaba:

str(data) 
'data.frame': 8 obs. of 8 variables: 
$ X1: num 0 0.0307 0.052 0.0637 0.0746 ... 
$ X2: num -0.0307 0 0.0213 0.033 0.0439 ... 
$ X3: num -0.052 -0.0213 0 0.0117 0.0226 ... 
$ X4: num -0.0637 -0.033 -0.0117 0 0.0109 ... 
$ X5: num -0.0746 -0.0439 -0.0226 -0.0109 0 ... 
$ X6: num -0.0983 -0.0676 -0.0462 -0.0345 -0.0237 ... 
$ X7: num -0.1336 -0.1029 -0.0815 -0.0698 -0.059 ... 
$ X8: num -0.1638 -0.133 -0.1117 -0.1 -0.0892 ... 

Y, a continuación,

a<-c("1M","3M","6M","9M","1Y","2Y","5Y","10Y") 
impl_spread[,ncol(impl_spread)+1]<-a 
attach(impl_spread) 
impl_spread.m<-melt(impl_spread) 
impl_spread.m <- ddply(impl_spread.m, .(variable), transform, rescale = rescale(value)) 
ggplot(impl_spread.m,aes(V9," ")) + geom_tile(aes(fill = rescale), 
colour = "white") + scale_fill_gradient(low = "white", high = "steelblue") 

Esto no parece producir la derecha trama. Por favor ayuda.

Gracias de antemano.

Answer 1

Prueba de esto,

library(reshape2) 
library(ggplot2) 
m = matrix(rnorm(20),5) 
ggplot(melt(m), aes(Var1,Var2, fill=value)) + geom_raster()