Estoy trazando coeficientes de correlación (valores = 0.0: 1.0) para dos isótopos medidos en cada individuo de dos poblaciones. Me gustaría tener una relación de aspecto fija para mi diagrama de dispersión para que los ejes X e Y tengan exactamente el mismo tamaño sin importar el dispositivo gráfico. ¿Sugerencias?

Esta es mi primera trama en R, ¿se agradece algún comentario sobre las mejoras en mi código? Finalmente, ¿vale la pena invertir en aprender las técnicas básicas de trazado o debo saltar directamente a ggplot2 o enrejado?

Mi guión de trama:

## Create dataset
WW_corr <-
structure(list(South_N15 = c(0.7976495, 0.1796725, 0.5338347,
0.4103769, 0.7447027, 0.5080296, 0.7566544, 0.7432026, 0.8927161
), South_C13 = c(0.76706752, 0.02320767, 0.88429902, 0.36648357,
0.73840937, 0.0523504, 0.52145159, 0.50707858, 0.51874445), North_N15 = c(0.7483608,
0.4294148, 0.9283554, 0.8831571, 0.5056481, 0.1945943, 0.8492716,
0.5759033, 0.7483608), North_C13 = c(0.08114805, 0.47268136,
0.94975596, 0.06023815, 0.33652839, 0.53055943, 0.30228833, 0.8864435,
0.08114805)), .Names = c("South_N15", "South_C13", "North_N15",
"North_C13"), row.names = c(NA, -9L), class = "data.frame")

opar <- par()

## Plot results
par(oma = c(1, 0, 0, 0), mar = c(4, 5, 2, 2))           
plot(1,1,xlim=c(0:1.0), ylim=c(0:1.0), type="n", las=1, bty="n", main = NULL,
     ylab=expression(paste("Correlation Coefficient (r) for ", delta ^{15},"N ",
                     "\u0028","\u2030","\u0029")),
     xlab=expression(paste("Correlation Coefficient (r) for ", delta ^{13},"C ",
                     "\u0028","\u2030","\u0029")))

points(WW_corr$South_N15, WW_corr$South_C13, pch = 23, cex = 1.25, 
       bg ="antiquewhite4", col = "antiquewhite4")
points(WW_corr$North_N15, WW_corr$North_C13, pch = 15, cex = 1.25,
       bg ="black")
axis(1, at = seq(0, 1.0, by = 0.1), labels = F, tick = TRUE, tck = -0.01)
axis(2, at = seq(0, 1.0, by = 0.1), labels = F, tick = TRUE, tck = -0.01)
abline(h=.86, v=.86, col = "gray60", lty = 2)
legend("topleft", c("North", "South"), pch = c(15, 23), 
       col = c("black", "antiquewhite4"), pt.bg = c("black", "antiquewhite4"),
       horiz=TRUE, bty = "n")

par(opar)