addInterval             Draw intervals or arrows on plots.
add_bars                Adding bars to an existing plot.
add_n_points            Add groups of points to a plot
alpha                   Adjusting the transparency of colors.
alphaPalette            Manipulate the transparency in a palette.
axesLabels              Format axes labels.
check_normaldist        Compare distribution of data with normal
                        distribution.
color_contour           Creates a contour plot with colored background.
convertFile             Replacing separators (for example, decimal and
                        thousand separators).
dotplot_error           Utility function
drawDevArrows           Draw arrows between different plots.
emptyPlot               Utility function
errorBars               Add error bars to a plot.
fill_area               Utility function
findAbsMin              Return the value (or the element with the
                        value) closest to zero.
find_n_neighbors        Return n neighbors around given indices.
firstLetterCap          Capitalize first letter of a string.
getArrowPos             Converts coordinates in current plot region to
                        device positions (in inch).
getCoords               Convert proportions into coordinates of the
                        plot or figure region.
getDec                  Return the number of decimal places.
getFigCoords            Get the figure region as coordinates of the
                        current plot region, or as corrdinates of the
                        figure region.
getProps                Transform coordinates into proportions of the
                        figure or plot region.
getRange                Function for rounding and/or segmenting a
                        range.
getRatioCoords          Move a vector n elements forward or backward.
get_palette             Retrieve the color scheme for contour plots.
gradientLegend          Add a gradient legend to a plot.
group_sort              Sort split by grouping predictor.
img                     Image object.
inch2coords             Convert device position (inch) to coordinates
                        in current plot region.
isColor                 Check whether color specifications exists.
keepFigRatio            Calculate the height or width in plot
                        coordinates to keep a given ratio relative to
                        the figure.
legend_margin           Add legend with respect to figure instead of
                        plot region.  Allows to move legend to margin
                        of plot.
list2str                Combine list values as string.
marginDensityPlot       Plot density of distribution in margins of the
                        plot.
move_n_point            Move a vector n elements forward or backward.
orderBoxplot            Order boxplot stats following a given ordering.
plot_error              Utility function
plot_image              Add images to plots.
plot_signifArea         Creates a colored surface plot from data frame
                        input.
plotsurface             Creates a colored surface plot from data frame
                        input.
se                      Calculate standard error of the mean.
sortBoxplot             Produce box-and-whisker plot(s) ordered by
                        function such as mean or median.
sortGroups              Sort groups based on a function such as mean
                        value or deviation.
