# view_xifti_surface

0th

Percentile

##### View cortical surface

Visualize "xifti" cortical data using an interactive Open GL window made with rgl. The rgl and fields packages are required.

##### Usage
view_xifti_surface(
xifti,
idx = NULL,
hemisphere = NULL,
view = c("both", "lateral", "medial"),
width = NULL,
height = NULL,
zoom = NULL,
bg = NULL,
title = NULL,
cex.title = NULL,
text_color = "black",
save = FALSE,
close_after_save = TRUE,
fname = "xifti",
colors = NULL,
color_mode = NULL,
zlim = NULL,
surfL = NULL,
surfR = NULL,
qualitative_colorlegend = TRUE,
colorlegend_ncol = NULL,
colorbar_embedded = TRUE,
colorbar_digits = NULL,
alpha = 1,
edge_color = NULL,
vertex_color = NULL,
vertex_size = 0,
border_color = NULL,
widget_idx_warn = NULL,
render_rgl = TRUE,
mode = NULL
)view_cifti_surface(
xifti,
idx = NULL,
hemisphere = NULL,
view = c("both", "lateral", "medial"),
width = NULL,
height = NULL,
zoom = NULL,
bg = NULL,
title = NULL,
cex.title = NULL,
text_color = "black",
save = FALSE,
close_after_save = TRUE,
fname = "xifti",
colors = NULL,
color_mode = NULL,
zlim = NULL,
surfL = NULL,
surfR = NULL,
colorbar_embedded = TRUE,
colorbar_digits = NULL,
alpha = 1,
edge_color = NULL,
vertex_color = NULL,
vertex_size = 0,
widget_idx_warn = NULL,
render_rgl = TRUE,
mode = NULL
)viewCIfTI_surface(
xifti,
idx = NULL,
hemisphere = NULL,
view = c("both", "lateral", "medial"),
width = NULL,
height = NULL,
zoom = NULL,
bg = NULL,
title = NULL,
cex.title = NULL,
text_color = "black",
save = FALSE,
close_after_save = TRUE,
fname = "xifti",
colors = NULL,
color_mode = NULL,
zlim = NULL,
surfL = NULL,
surfR = NULL,
colorbar_embedded = TRUE,
colorbar_digits = NULL,
alpha = 1,
edge_color = NULL,
vertex_color = NULL,
vertex_size = 0,
widget_idx_warn = NULL,
render_rgl = TRUE,
mode = NULL
)viewcii_surface(
xifti,
idx = NULL,
hemisphere = NULL,
view = c("both", "lateral", "medial"),
width = NULL,
height = NULL,
zoom = NULL,
bg = NULL,
title = NULL,
cex.title = NULL,
text_color = "black",
save = FALSE,
close_after_save = TRUE,
fname = "xifti",
colors = NULL,
color_mode = NULL,
zlim = NULL,
surfL = NULL,
surfR = NULL,
colorbar_embedded = TRUE,
colorbar_digits = NULL,
alpha = 1,
edge_color = NULL,
vertex_color = NULL,
vertex_size = 0,
widget_idx_warn = NULL,
render_rgl = TRUE,
mode = NULL
)
##### Arguments
xifti

Object of class "xifti". See is.xifti and make_xifti.

idx

The time/column index of the data to display. If its length is greater than one and save==FALSE, use the widget instead of the OpenGL window to view the plot interactively, because the widget's slider will control what time/column is being displayed in the widget whereas all meshes will be rendered on top of one another in the Open GL window.

hemisphere

Which brain cortex to display: "both", "left", or "right". Each will be plotted in a separate panel column.

If a brain cortex is requested but no surface is available, a default inflated surface will be used.

This argument can also be NULL (default). In this case, the default inflated surface included with ciftiTools will be used for each cortex with data (i.e. if xifti$data$cortex_left and/or xifti$data$cortex_right exist).

Surfaces without data will be colored white.

view

Which view to display: "lateral", "medial", or "both". If NULL (default), both views will be shown. Each view will be plotted in a separate panel row.

width

The dimensions of the RGL window, in pixels. If both are NULL (default), the dimensions will be set to 1000 (width) x 700 (height) for 1x1 and 2x2 subplots, 1500 x 525 for 2x1 subplots, and 500 x 700 for 1x2 subplots. These defaults are chosen to fit comfortably within a 1600 x 900 screen. Specyfing only one will set the other to maintain the same aspect ratio. Both can be specified to set the dimensions exactly.

height

The dimensions of the RGL window, in pixels. If both are NULL (default), the dimensions will be set to 1000 (width) x 700 (height) for 1x1 and 2x2 subplots, 1500 x 525 for 2x1 subplots, and 500 x 700 for 1x2 subplots. These defaults are chosen to fit comfortably within a 1600 x 900 screen. Specyfing only one will set the other to maintain the same aspect ratio. Both can be specified to set the dimensions exactly.

zoom

Adjustment to size of brain meshes. Default: 3/5 (100% + 3/5*100% = 160% the original size).

bg

Background color. NULL will not color the background (white).

title

Optional title(s) for the plot(s). It will be printed at the top in a separate subplot with 1/4 the height of the brain cortex subplots.

Default: NULL will use the time index (".dtseries") or name (.dscalar or .dlabel) of the data column being plotted.

To use a custom title(s), use a length 1 character vector (same title for each plot) or length length(idx) character vector (different title for each plot). Set to an empty string "" to omit the title.

If the title is non-empty but does not appear, cex.title may need to be lowered.

cex.title

Font size multiplier for the title. NULL (default) will use 2 for titles less than 20 characters long, and smaller sizes for increasingly longer titles.

text_color

Color for text in title and colorbar legend. Default: "black".

save

Save the plot to a .png file named by fname? Default: FALSE.

close_after_save

If save==TRUE, close the interactive Open GL window at the end of this function call? Default: TRUE.

fname

An identifier to use for naming the saved images ("[fname].png") or video frames ("[fname]_1.png", "[fname]_2.png", ...). Default: "xifti" for xifti_view_surface and "surf" for view_surf.

colors

(Optional) "ROY_BIG_BL", vector of colors to use, OR the name of a ColorBrewer palette (see RColorBrewer::brewer.pal.info and colorbrewer2.org). Defaults are "ROY_BIG_BL" (sequential), "Set2" (qualitative), and "ROY_BIG_BL" (diverging). An exception to these defaults is if the "xifti" object represents a .dlabel CIFTI (intent 3007), then the qualitative colors in the label table will be used. See the ciftiTools::make_color_pal() description for more details.

color_mode

(Optional) "sequential", "qualitative", or "diverging". NULL will use the qualitative color mode if the "xifti" object represents a .dlabel CIFTI (intent 3007), and the sequential color mode otherwise. See the ciftiTools::make_color_pal() description for more details.

zlim

(Optional) Controls the mapping of values to each color in colors. If the length is longer than one, using -Inf will set the value to DATA_MIN, and Inf will set the value to DATA_MAX. See the ciftiTools::make_color_pal() description for more details.

surfL, surfR

(Optional if xifti$surf$cortex_left and xifti$surf$cortex_right are not empty) The brain surface model to use. Each can be a file path for a GIFTI, a file read by gifti::readgii, or a list with components "vertices" and "faces". If provided, they will override xifti$surf$cortex_left and xifti$surf$cortex_right if they exist. Otherwise, leave these arguments as NULL (default) to use xifti$surf$cortex_left and xifti$surf$cortex_right.

qualitative_colorlegend

If color_mode=="qualitative", should the colorbar be replaced with a color legend? It will be printed separately from the RGL window. Default: TRUE.

colorlegend_ncol

Number of columns in color legend. If NULL (default), use 10 entries per row. Only applies if the color legend is drawn (qualitative_colorlegend is TRUE and the qualitative color mode is used).

colorbar_embedded

Should the colorbar be embedded in the plot? It will be positioned in the bottom-left corner, in a separate subplot with 1/4 the height of the brain cortex subplots. Default: TRUE. If FALSE, print it separately instead.

colorbar_digits

The number of digits for the colorbar legend ticks. If NULL (default), let format decide.

alpha

Transparency value for mesh coloring, between 0 and 1. Default: 1.0 (no transparency).

edge_color

Outline each edge in this color. Default: NULL (do not outline the edges).

vertex_color

Draw each vertex in this color. Default: "black". Vertices are only drawn if vertex_size > 0

vertex_size

Draw each vertex with this size. Default: 0 (do not draw the vertices).

border_color

Only applicable if color_mode is "qualitative". Border vertices will be identified (those that share a faces with at least one vertex of a different value) and drawn in this color instead, overriding the color indicated by their value. If NULL, do not draw borders.

widget_idx_warn

If save==FALSE or close_after_save==FALSE, each mesh must be rendered in the same window. This is problematic if idx and the mesh size are large. So, this option can be used to print a warning when length(idx) exceeds widget_idx_warn and the meshes are being drawn in the same window. Use Inf to never print a warning. The default, NULL, will print a warning if idx times the number of vertices exceeds 200k (approximately three 32k meshes for both the left and right hemisphere.)

render_rgl

Default: TRUE. If FALSE, do not render the Open GL window, widget, or image(s). Instead, return the rgl mesh objects and coloring information. This should be used by developers only.

mode

Deprecated: has no effect and will be removed. See save and close_after_save.

##### Value

If save and close_after_save, the name(s) of the image file(s) that were written.

Otherwise, if the length of idx is equal to one, a list of the rgl object IDs which can be used to further manipulate the Open GL window; if the length of idx is greater than one, the htmlwidget with slider to interactively control which timepoint is being displayed.

##### Navigating and Embedding the Interactive Plots

This function opens an interactive Open GL window rendered by rgl. If save==TRUE and close_after_save==TRUE, the window will be closed after the function call. Otherwise, it is kept open and the following information applies:

To navigate the plot, left click and drag the cursor to rotate. Use the scroll wheel or right click and drag to zoom. Press the scroll wheel and drag to change the field-of-view. Execute snapshot to save the current window as a .png file. Execute rgl.close to close the window. rgl.viewpoint can be used for programmatic navigation.

The Open GL window can be embedded as an htmlwidget in an R Markdown document using one of two methods. The first is executing rglwidget in the chunk where the plot is made. This first method should work within both the RStudio IDE and a knitted .html file. The second method is executing setupKnitr at the start of the document and then using the chunk option webgl=TRUE in the chunk where the plot is made. The second method is specifically for knitted .html files. Although the first method is the newest approach and is recommended by others, we used the second method in the ciftiTools vignette because the first is not compatible with htmlpreview. For both methods, the window still needs to be open to render the widget. Also for both methods, you will probably need to tweak the image dimensions e.g. fig.width=8, fig.height=5 in the chunk options, because it uses the defaults from RMarkdown/Knitr instead of what makes sense based on the dimensions of the Open GL window.

For view_xifti_surface, if length(idx) > 1, this function will automaticaly return an htmlwidget using the first method, but with a playwidget wrapper to add a slider to control which column index is being displayed. All the meshes will be rendered on top of one another in the Open GL window, so only the widget will be useful for viewing the data interactively. Since it uses the first method, it will not be visible with htmlpreview. No additional call to rglwidget is necessary, but rgl.close must be called in a following chunk to close the Open GL window.

##### Embedding the Static Plots

If save==TRUE, the plot(s) is written to a .png file. (For view_xifti_surface, if length(idx) > 1, each idx will be written to a separate image file.) You can use include_graphics to embed an image file in an R Markdown document. If close_after_save==TRUE, the return value of this function call is the name(s) of the image file(s) that were written, so it can be used directly to display the image.

There's an additional way to embed an image of this plot without writing a .png file: use save==FALSE and set the chunk options rgl=TRUE, format="png". You will probably need to tweak the image dimensions e.g. fig.width=8, fig.height=5 in the chunk options, because it uses the defaults from RMarkdown/Knitr instead of what makes sense based on the dimensions of the Open GL window.

##### Aliases
• view_xifti_surface
• view_cifti_surface
• viewCIfTI_surface
• viewcii_surface
Documentation reproduced from package ciftiTools, version 0.1.6.0, License: GPL-3

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