install.packages("copula")
install.packages("plot3D")
library(copula)
library(plot3D)

delta <- 0.9
fgm_cop <- fgmCopula(param = delta)
u <- seq(0, 1, length.out = 45)
v <- seq(0, 1, length.out = 45)
grid <- expand.grid(u = u, v = v)
grid_matrix <- as.matrix(grid)
C_uv <- pCopula(grid_matrix, fgm_cop)
c_uv <- dCopula(grid_matrix, fgm_cop)
C_matrix <- matrix(C_uv, nrow = length(u), byrow = FALSE)
c_matrix <- matrix(c_uv, nrow = length(u), byrow = FALSE)

# (a) Wireframe C(u,v)
persp(x = u, y = v, z = C_matrix,
        theta = -30, phi = 31, expand = 0.65,
        cex.axis = 0.65,cex.lab  = 0.95,
        col = "#00FFFF", border = "black",
        xlab = "u", ylab = "v", zlab = "C(u,v)",
        ticktype = "detailed",
        main = "")

# (b) Contour C(u,v)
contour(u, v, C_matrix,
        cex.axis = 0.65,cex.lab  = 0.95,
        xlab = "u", ylab = "v",
        main = "",
        col = heat.colors(20), lwd = 3)

# (c) Wireframe c(u,v)
persp(x = u, y = v, z = c_matrix,
        theta = -32.5, phi = 35, expand = 0.75,
        cex.axis = 0.65,cex.lab  = 0.95,
        col = "#00FFFF", border = "black",
        xlab = "u", ylab = "v", zlab = "C(u,v)",
        ticktype = "detailed",
        main = "")

# (d) Contour c(u,v)
contour(u, v, c_matrix,
        cex.axis = 0.65,cex.lab  = 0.95,
        xlab = "u", ylab = "v",
        main = "",
        col = heat.colors(20), lwd = 1.5)<pre>An Error occurred while handling another error:
yii\web\HeadersAlreadySentException: Headers already sent in  on line 0. in /var/www/html/prof-homepages/vendor/yiisoft/yii2/web/Response.php:366
Stack trace:
#0 /var/www/html/prof-homepages/vendor/yiisoft/yii2/web/Response.php(339): yii\web\Response-&gt;sendHeaders()
#1 /var/www/html/prof-homepages/vendor/yiisoft/yii2/web/ErrorHandler.php(136): yii\web\Response-&gt;send()
#2 /var/www/html/prof-homepages/vendor/yiisoft/yii2/base/ErrorHandler.php(135): yii\web\ErrorHandler-&gt;renderException()
#3 [internal function]: yii\base\ErrorHandler-&gt;handleException()
#4 {main}
Previous exception:
yii\web\HeadersAlreadySentException: Headers already sent in  on line 0. in /var/www/html/prof-homepages/vendor/yiisoft/yii2/web/Response.php:366
Stack trace:
#0 /var/www/html/prof-homepages/vendor/yiisoft/yii2/web/Response.php(339): yii\web\Response-&gt;sendHeaders()
#1 /var/www/html/prof-homepages/vendor/yiisoft/yii2/base/Application.php(656): yii\web\Response-&gt;send()
#2 /var/www/html/prof-homepages/vendor/faravaghi/yii2-filemanager/models/Files.php(696): yii\base\Application-&gt;end()
#3 /var/www/html/prof-homepages/vendor/faravaghi/yii2-filemanager/controllers/FilesController.php(484): faravaghi\filemanager\models\Files-&gt;getFile()
#4 [internal function]: faravaghi\filemanager\controllers\FilesController-&gt;actionGetFile()
#5 /var/www/html/prof-homepages/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array()
#6 /var/www/html/prof-homepages/vendor/yiisoft/yii2/base/Controller.php(180): yii\base\InlineAction-&gt;runWithParams()
#7 /var/www/html/prof-homepages/vendor/yiisoft/yii2/base/Module.php(528): yii\base\Controller-&gt;runAction()
#8 /var/www/html/prof-homepages/vendor/yiisoft/yii2/web/Application.php(103): yii\base\Module-&gt;runAction()
#9 /var/www/html/prof-homepages/vendor/yiisoft/yii2/base/Application.php(386): yii\web\Application-&gt;handleRequest()
#10 /var/www/html/prof-homepages/backend/web/index.php(16): yii\base\Application-&gt;run()
#11 {main}</pre>