Hi

Base graphics is designed for drawing everything in a figure before moving on to the next figure. Also, 'mfg' can only be set via par().
Are you looking for something like this ... ?


par(mfrow = c(2, 2))
for (i in 1:2) {
    for (j in 1:2) {
        par(mfg = c(i, j))
        plot(c(0, 1), c(0, 1), type = "n")
        text(0.5, 0.5, labels = paste("(", i, ",", j, ")"))
    }
}


If you really want to revisit previous figures, you might try split.screen(), but it is pretty fragile and, as the example below shows, still not designed for revisiting a previous *plot* (just a previous figure region) ...


split.screen(c(2, 2))
for (i in 1:4) {
    screen(i)
    plot(c(0, 1), c(0, 1), type = "n")
}
for (i in 1:2) {
    for (j in 1:2) {
        screen(2*(i - 1) + j)
        text(0.5, 0.5, labels = paste("(", i, ",", j, ")"))
    }
}


If you REALLY want to revisit previous drawing, you might need to look at {grid} viewports, which are designed to allow you to get back to the original drawing context ...


library(grid)
grid.newpage()
pushViewport(viewport(layout=grid.layout(2, 2)))
for (i in 1:2) {
    for (j in 1:2) {
        pushViewport(viewport(layout.pos.row=i, layout.pos.col=j,
                              name=paste0(i, j)))
        grid.rect(width=.8, height=.8)
        upViewport()
    }
}
for (i in 1:2) {
    for (j in 1:2) {
        downViewport(paste0(i, j))
        grid.text(paste("(", i, ",", j, ")"))
        upViewport()
    }
}


Paul


On 13/11/25 07:28, Naresh Gurbuxani wrote:
After drawing multiple figures, I want to select an earlier figure to add some 
low level commands.  Using mfg parameter runs all commands in the most recent 
figure only.  How can an earlier figure be selected?

Thanks,
Naresh

par(mfrow = c(2, 2))
for (i in 1:4) plot(c(0, 1), c(0, 1), type = "n”)
for (i in 1:2) {for (j in 1:2) text(0.5, 0.5, labels = paste("(", i, ",", j, 
")"), mfg = c(i, j, 2, 2))}
#All text is in bottom right figure only
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--
Dr Paul Murrell (he/him)
Te Kura Tatauranga | Department of Statistics
Waipapa Taumata Rau | The University of Auckland
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64 9 3737599 x85392
[email protected]
www.stat.auckland.ac.nz/~paul/

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and provide commented, minimal, self-contained, reproducible code.

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