add whitelist and a bit of help for jasp-stats/jasp-issues#516

Common/r_functionwhitelist.cpp

@@ -245,7 +245,17 @@ const std::set<std::string> R_FunctionWhiteList::functionWhiteList {
 	"pbirthday",
 	"ptukey",
 	"dwilcox",
-	"switch"
+	"switch",
+	"rowMean",			"rowMeanNaRm",
+	"rowSum",			"rowSumNaRm",		
+	"rowSD",			"rowSDNaRm",	
+	"rowVariance",		"rowVarianceNaRm",	
+	"rowCovariance",	
+	"rowCorrelation",
+	"rowMedian",		"rowMedianNaRm",	
+	"rowMin",			"rowMinNaRm",	
+	"rowMax",			"rowMaxNaRm"
+
 #ifdef JASP_DEBUG
 	,"Sys.sleep", ".crashPlease", "stringi::stri_enc_mark", "stringi::stri_enc_toutf8", "Encoding"
 #endif

Resources/Help/other/computedcolumns.html

@@ -46,9 +46,18 @@ <h1>Computed Columns</h1>
 				</li>
 			</ul>
 			There are of course many possibilities and you are only limited by the availability of (safe) functions in JASP. Should you miss something than don't hesitate to contact us so we may add it to the next version.
-	</p>
-
-
+	</p>	
 </details>
 
+<details>
+	<summary><b>Rowwise operations</b></summary>
+	<p>
+		A special type of computed column creation only available in R is the rowwise operations of mean, variance etc.<br><br>
+		These functions are:<br>
+		<code>rowMean, rowSum, rowSD, rowVariance, rowCovariance, rowCorrelation, rowMedian, rowMin, rowMax</code><br>
+		They will probably return NA for when any of the column's rows contain one.
+		So there are also variants like <code>rowMeanNaRm</code> available that drop NA first.<br><br>
+		It can be used like: <code>rowMean(Column 1, Column 2, Column 3)</code>
+	</p>
+</details>