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<p>Trocando a ordem para ficar como eu queria (na primeira imagem):<br>
</p>
<span style="font-family:monospace,monospace">library(Matrix)</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">library(latticeExtra)</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">library(gridExtra)</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"></span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">m1 <- sparseMatrix(i =
c(1, 1, 2, 3, 4, 4, 4, 5),</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"> j =
c(3, 4, 4, 1, 2, 3, 5, 4),</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"> x =
1:8)</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"></span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">m2 <- m1/2</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"></span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">p1 <- image(m1) +</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"> layer(panel.text(x =
3,</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"> y =
3,</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">
labels = "Olá mundo.",</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"> col =
"red"))</span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace"></span><br>
<span style="font-family:monospace,monospace"></span><span
style="font-family:monospace,monospace">grid.arrange(p1,
image(m2), ncol = 2)</span><br>
<span style="font-family:monospace,monospace"></span><br>
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