<span style="color:#0000CD;">Tentei rodar vosso código, mas veja o que aconteceu mais abaixo!</span><br />
<br />
> da <- data.frame(Tree=rep(c("CB6", "CB7", "MB10"), each=8), ID=rep(1:8, 3),<br />
+ AZ=c(240.7, 276.6, 301.1, 51.9, 110.8, 130, NA, NA, 211.3, 182.1, <br />
+ 178, 111.6, 29.4, 13.8, 307.7, 274.2, 325.5, 228.8, 192.9, 138.9,<br />
+ 92.4, 35.9, 330.8, NA), <br />
+ DH=c(3.6, 5.6, 3.3, 3.3, 2.5, 6.4, NA, NA, 4.5, 4.3, 3.4, 4.6, 2.4, <br />
+ 4.5, 7.6, 3.2, 6.1, 10, 3.2, 3.9, 6.9, 4.2, 3.4, NA))<br />
> <br />
> ### remove NA's e calcula coordenadas x e y<br />
> da <- da[complete.cases(da),]<br />
> da$x = da$DH*cos(da$AZ*pi/180)<br />
> da$y = da$DH*sin(da$AZ*pi/180)<br />
> da<br />
Tree ID AZ DH x y<br />
1 CB6 1 240.7 3.6 -1.7617768 -3.1394494<br />
2 CB6 2 276.6 5.6 0.6436480 -5.5628875<br />
3 CB6 3 301.1 3.3 1.7045600 -2.8256814<br />
4 CB6 4 51.9 3.3 2.0362184 2.5968856<br />
5 CB6 5 110.8 2.5 -0.8877674 2.3370642<br />
6 CB6 6 130.0 6.4 -4.1138407 4.9026844<br />
9 CB7 1 211.3 4.5 -3.8450647 -2.3378360<br />
10 CB7 2 182.1 4.3 -4.2971121 -0.1575679<br />
11 CB7 3 178.0 3.4 -3.3979288 0.1186583<br />
12 CB7 4 111.6 4.6 -1.6933729 4.2769718<br />
13 CB7 5 29.4 2.4 2.0909131 1.1781690<br />
14 CB7 6 13.8 4.5 4.3701043 1.0734006<br />
15 CB7 7 307.7 7.6 4.6476055 -6.0132989<br />
16 CB7 8 274.2 3.2 0.2343622 -3.1914063<br />
17 MB10 1 325.5 6.1 5.0271698 -3.4550780<br />
18 MB10 2 228.8 10.0 -6.5868946 -7.5241491<br />
19 MB10 3 192.9 3.2 -3.1192358 -0.7144004<br />
20 MB10 4 138.9 3.9 -2.9388972 2.5637635<br />
21 MB10 5 92.4 6.9 -0.2889420 6.8939475<br />
22 MB10 6 35.9 4.2 3.4021749 2.4627639<br />
23 MB10 7 330.8 3.4 2.9679351 -1.6587228<br />
> <br />
> ### "fecha" polígonos<br />
> da2 <- NULL<br />
> for (tree in unique(da$Tree)) {<br />
+ sel <- da[da$Tree==tree,]<br />
+ sel <- rbind(sel, sel[1,])<br />
+ da2 <- rbind(da2, sel)<br />
+ }<br />
> <br />
> ### visualiza formas das copas<br />
> par(mfrow=c(2,2))<br />
> for (tree in unique(da$Tree)) {<br />
+ sel <- da[da$Tree==tree,]<br />
+ plot(sel$y~sel$x, type="n", asp=T, xlab=NA, ylab=NA, xlim=c(-10,10), ylim=c(-10,10))<br />
+ polygon(sel$y~sel$x, col="light green", bor=3)<br />
+ area <- paste(round(splancs::areapl(cbind(sel$x, sel$y)),2 ), "m²")<br />
+ text(6,6, area)<br />
+ }<br />
Error in loadNamespace(name) : there is no package called ‘splancs’<br />
> <br />
<p><br />
</p>
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<div class="gmail_default" style="font-family:verdana,sans-serif">Gabriel, bom dia!</div>
<div class="gmail_default" style="font-family:verdana,sans-serif"> </div>
<div class="gmail_default" style="font-family:verdana,sans-serif">Segue uma ideia inicial para seu caso. Considerei que as distâncias que você forneceu são de fato as distâncias horizontais e que os pontos foram tomados a partir de um único ponto de visada. Dê uma olhada no desenho das copas, de fato eu esperava copas mais circulares...</div>
<div class="gmail_default" style="font-family:verdana,sans-serif"> </div>
<div class="gmail_default" style="font-family:verdana,sans-serif"> </div>
<div class="gmail_default">
<div class="gmail_default"><span style="font-family:monospace,monospace">### <code r></span></div>
<div class="gmail_default">
<div class="gmail_default"><font face="monospace, monospace">da <- data.frame(Tree=rep(c("CB6", "CB7", "MB10"), each=8), ID=rep(1:8, 3),</font></div>
<div class="gmail_default"><font face="monospace, monospace"> AZ=c(240.7, 276.6, 301.1, 51.9, 110.8, 130, NA, NA, 211.3, 182.1, </font></div>
<div class="gmail_default"><font face="monospace, monospace"> 178, 111.6, 29.4, 13.8, 307.7, 274.2, 325.5, 228.8, 192.9, 138.9,</font></div>
<div class="gmail_default"><font face="monospace, monospace"> 92.4, 35.9, 330.8, NA), </font></div>
<div class="gmail_default"><font face="monospace, monospace"> DH=c(3.6, 5.6, 3.3, 3.3, 2.5, 6.4, NA, NA, 4.5, 4.3, 3.4, 4.6, 2.4, </font></div>
<div class="gmail_default"><font face="monospace, monospace"> 4.5, 7.6, 3.2, 6.1, 10, 3.2, 3.9, 6.9, 4.2, 3.4, NA))</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### remove NA's e calcula coordenadas x e y</font></div>
<div class="gmail_default"><font face="monospace, monospace">da <- da[complete.cases(da),]</font></div>
<div class="gmail_default"><font face="monospace, monospace">da$x = da$DH*cos(da$AZ*pi/180)</font></div>
<div class="gmail_default"><font face="monospace, monospace">da$y = da$DH*sin(da$AZ*pi/180)</font></div>
<div class="gmail_default"><font face="monospace, monospace">da</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### "fecha" polígonos</font></div>
<div class="gmail_default"><font face="monospace, monospace">da2 <- NULL</font></div>
<div class="gmail_default"><font face="monospace, monospace">for (tree in unique(da$Tree)) {</font></div>
<div class="gmail_default"><font face="monospace, monospace"> sel <- da[da$Tree==tree,]</font></div>
<div class="gmail_default"><font face="monospace, monospace"> sel <- rbind(sel, sel[1,])</font></div>
<div class="gmail_default"><font face="monospace, monospace"> da2 <- rbind(da2, sel)</font></div>
<div class="gmail_default"><font face="monospace, monospace">}</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### visualiza formas das copas</font></div>
<div class="gmail_default"><font face="monospace, monospace">par(mfrow=c(2,2))</font></div>
<div class="gmail_default"><font face="monospace, monospace">for (tree in unique(da$Tree)) {</font></div>
<div class="gmail_default"><font face="monospace, monospace"> sel <- da[da$Tree==tree,]</font></div>
<div class="gmail_default"><font face="monospace, monospace"> plot(sel$y~sel$x, type="n", asp=T, xlab=NA, ylab=NA, xlim=c(-10,10), ylim=c(-10,10))</font></div>
<div class="gmail_default"><font face="monospace, monospace"> polygon(sel$y~sel$x, col="light green", bor=3)</font></div>
<div class="gmail_default"><font face="monospace, monospace"> area <- paste(round(splancs::areapl(cbind(sel$x, sel$y)),2 ), "m²")</font></div>
<div class="gmail_default"><font face="monospace, monospace"> text(6,6, area)</font></div>
<div class="gmail_default"><font face="monospace, monospace">}</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### Exemplos de operações com um polígono</font></div>
<div class="gmail_default"><font face="monospace, monospace">p1 <- as.matrix(da2[1:7, 5:6])</font></div>
<div class="gmail_default"><font face="monospace, monospace">splancs::areapl(p1) # [1] 31.77187 m²</font></div>
<div class="gmail_default"><font face="monospace, monospace">p1.d <- as.matrix(dist(p1))</font></div>
<div class="gmail_default"><font face="monospace, monospace">p1.l <- sapply(1:(nrow(p1.d)-1), function(x) p1.d[x, x+1])</font></div>
<div class="gmail_default"><font face="monospace, monospace">sum(p1.l) # perimeter - 27.21928 m</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">require(sp) </font></div>
<div class="gmail_default"><font face="monospace, monospace">p1.sp <- SpatialPolygons(list(Polygons(list(Polygon(p1)), "pol1")))</font></div>
<div class="gmail_default"><font face="monospace, monospace">rgeos::gArea(p1.sp) # [1] 31.77187 m²</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">require(geosphere)</font></div>
<div class="gmail_default"><font face="monospace, monospace">areaPolygon(p1.sp) # 390888183993 ??? </font></div>
<div class="gmail_default"><font face="monospace, monospace">perimeter(p1.sp) # 3014297 ???</font></div>
<div class="gmail_default"><font face="monospace, monospace">### geosphere considera que seriam coordenadas em graus</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### é possível calcular um fator de conversão</font></div>
<div class="gmail_default"><font face="monospace, monospace">conv <- sqrt(areaPolygon(p1.sp)/rgeos::gArea(p1.sp)); conv # ~ 110919m</font></div>
<div class="gmail_default"><font face="monospace, monospace">areaPolygon(p1.sp)/conv^2 # 31.77187 m²</font></div>
<div class="gmail_default"><font face="monospace, monospace">perimeter(p1.sp)/conv # 27.17573 m</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### Cálculo para os três polígonos</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">for (tree in unique(da2$Tree)) {</font></div>
<div class="gmail_default"><font face="monospace, monospace"> sel <- da2[da2$Tree==tree, 5:6]</font></div>
<div class="gmail_default"><font face="monospace, monospace"> sel.sp <- SpatialPolygons(list(Polygons(list(Polygon(sel)), "pol1")))</font></div>
<div class="gmail_default"><font face="monospace, monospace"> conv <- sqrt(areaPolygon(sel.sp)/rgeos::gArea(sel.sp))</font></div>
<div class="gmail_default"><font face="monospace, monospace"> print(paste(tree, round(areaPolygon(sel.sp)/conv^2, 1), </font></div>
<div class="gmail_default"><font face="monospace, monospace"> round(perimeter(sel.sp)/conv, 1)))</font></div>
<div class="gmail_default"><font face="monospace, monospace">}</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace"># Área e perímetros</font></div>
<div class="gmail_default"><font face="monospace, monospace"># [1] "CB6 31.8 27.2"</font></div>
<div class="gmail_default"><font face="monospace, monospace"># [1] "CB7 48.1 31.3"</font></div>
<div class="gmail_default"><font face="monospace, monospace"># [1] "MB10 74 40.8"</font></div>
<div class="gmail_default"> </div>
<div class="gmail_default"><font face="monospace, monospace">### </code></font></div>
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<font face="arial, helvetica, sans-serif" style="font-size:12.8px"><span style="font-size:small">================================================</span><br />
Éder Comunello</font>
<div style="font-size:12.8px"><span style="font-family:arial,helvetica,sans-serif">Agronomist (UEM), MSc in Environ. Sciences (UEM)</span></div>
<div style="font-size:12.8px">
<div style="font-size:small"><span style="font-family:arial,helvetica,sans-serif">DSc in Agricultural Systems Engineering (USP/Esalq)</span></div>
<div><span style="font-size:small">Brazilian Agricultural Research Corporation (</span><font face="arial, helvetica, sans-serif" style="font-size:small">Embrapa)</font></div>
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<div><font face="arial, helvetica, sans-serif" style="font-size:small">Dourados, MS, Brazil </font><font face="arial, helvetica, sans-serif" size="2">|<O>|</font></div>
<div style="font-size:small"><span style="font-family:arial,helvetica,sans-serif">================================================</span></div>
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<div style="font-size:small"><font face="arial, helvetica, sans-serif">GEO, </font>-22.2752, -54.8182, 408m</div>
<div style="font-size:12.8px"><span style="font-size:small;font-family:arial,helvetica,sans-serif">UTC-04:00 / DST: UTC-03:00</span></div>
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