Change edge color in preview panel - gephi

I am plotting a graph in Gephi. I used an edge attribute (negative and positive correlation) in the overview panel; it was good.
But the overview panel does not give me an as visually appealing image like the preview panel. However, the preview panel does not have the function of changing the edge color according to my attribute. Does anybody know how to change that?
In addition, sometimes the preview panel refreshes forever and has no result. Moreover, the figure in overview panel is small; when I zoom-in the text becomes vague.

… the preview panel does not have the function of changing the attribute for edge to color my edge according to my attribute. Does anybody know how to change that?
Edge coloring in Preview tab can be adjusted via:
Preview > Preview Settings > Settings > Edges > Color
Following options are available:
Original
Colors edges according to color(s) set in Overview tab.
Mixed
Colors edges by fading source- and target node's color.
Source
Colors edges according to edge's source node color.
Target
Colors edges according to edge's target node color.
Custom
Colors edges according to a single selectable color.
… sometimes the preview panel refreshes forever and has no result.
Update Java, or position view to include all nodes:
Preview > Preview > Reset zoom
Disable display of a percentage of the graph (in case rendering takes too long):
Preview > Preview Settings > Settings > Preview ratio

Related

Mirror the scale from the bottom axis to also appear in the top axis

I have a simple 0-100 range of values representing percent using HorizontalBar and the TChart (Embarcadero edition) appears on a ScrollBox in this FMX app because I don't like the panning behavior I've seen in this Delphi 10.3.3 app for Windows. But the use of the ScrollBox means that sometimes the Bottom Axis is not visible, so I would like to have its Scale repeated as the TopAxis Scale.
Just having the Visible box checked for the Scale of the TopAxis does not produce the desired result.
Currently, I have a crude work-around that uses a separate chart that only exposes its BottomAxis Scale, positioned as a TopAxis Scale in the TChart that shows the data.
Is there a way to specify having the same scale on the bottom and top of one TChart?
On the series set the general option "Horizontal Axis" to Top and Bottom and for "Vertical Axis" to Left and Right.

Remove color cast using libvips

I have sRGB images with color casts. To remove it manually I usually use Photoshop Level Adjustments. Photoshop also have tools for that: Auto Contrast or even better Auto Tone which also takes shadows, midtones & highlights into account.
If I remove the cast manually I adjust each of the RGB channels individually so that the darkest pixels are set to pure black and the lightest to pure white and then redistribute all other values (spreading the histogram). This is a simple approach but shows good results for my images.
In my node.js app I'm using sharp for image processing which uses libvips as its processing engine. I tried to remove the cast with .normalize() but this command works on all channels together and not individual for each of the RGB channels. So it doesn't work for me.
I also asked this question on the sharp project page. I tested the suggestion from lovell to try it with hist_local but the results are not useable for me.
Now I would like to find out how this could be done using the native libvips. I've played around with nip2 GUI and different commands but could not figure out how it could be achieved:
Histogram > Equalise Histogram > Global => Picture looks over saturated
Image > Levels > Scale to 0 - 255 => Channels ar not all spreading from 0 - 255 (I don't understand exactly what this command does?)
Thanks for every hint!
Addition
Here is a example with pictures from Photoshop to show what I want.
The source image is a picture of a frame from a film negative.
Image before processing
Step1 Invert image
Image after inversion
Step2 using Auto tone in Photoshop (works the same way as my description above about manually remove the color cast)
Image after Auto Tone
This last picture is ok for me.
nip2 has a menu item for this.
Load your image and mark a region on it containing the area you'd like to be neutral. It can be any lightness, it doesn't need to be white.
Use File / Open to get the file dialog and you should see the image loaded in your workspace as a thumbnail.
Doubleclick on the thumbnail to open an image view window.
In the view window, zoom and pan to the right spot. The user guide (press F1) has a section on image navigation.
Hold down CTRL and click and drag down and right to mark a rectangular region.
Back in the main window, click Toolkits / Tasks / Capture / White balance. You should see something like:
You can drag an resize your region to change the neutral point. Use the colour picker to set what white means. You can make other whites with (for example) Colour / New / Colour from CCT and link them together.
Click Colour / New / Colour from CCT to make a colour picker from CCT (correlated colour temperature) -- the temperature in Kelvin of that white.
Set it to something interesting, like 4800 for warm white.
Click on the formula for A5.white to edit it, and enter the cell of your CCT widget (A7 in this case).
Now you can drag the region to adjust the pixels to set the neutral from, and drag the CCT slider to set the temperature.
It can be annoying to find things in the toolkit menu. There's a thing for searching toolkits: in the main window, click View / Toolkit browser. You can enter something like "white" and it'll show related toolkit entries.
Here's another answer, but using pyvips and responding to the previous comments. I didn't want to delete the first answer as it still seemed useful.
This version finds the image histogram, searches for thresholds which will select 0.5% and 99.5% of pixels in each image band, then rescales the image so that those pixel values become 0 and 255.
import sys
import pyvips
# trim off this percentage of pixels from the top and bottom
trim_percent = 0.5
def percent(hist, percentage):
"""From a histogram, find the threshold above which lie
#percentage of pixels."""
# normalised cumulative histogram
norm = hist.hist_cum().hist_norm()
# column and row profile over percentage
c, r = (norm > norm.width * percentage / 100).profile()
return r.avg()
image = pyvips.Image.new_from_file(sys.argv[1])
# photographic negative
image = image.invert()
# find image histogram, split to set of separate bands
bands = image.hist_find().bandsplit()
# for each band, the low and high thresholds
low = [percent(band, trim_percent) for band in bands]
high = [percent(band, 100 - trim_percent) for band in bands]
# rescale image
scale = [255.0 / (h - l) for h, l in zip(high, low)]
image = (image - low) * scale
image.write_to_file(sys.argv[2])
It seems to give roughly similar results to the PS button. If I run:
$ ./autolevel.py ~/pics/before.jpg x.jpg
I see:
In the meantime I've found the Simplest Color Balance Algorithm which exactly describes the problem with color casts and there you can also find a C source code.
It is exactly the same solution as John describes in his second answer but as a small piece of c-code.
I'm now trying to use it as C/C++ addon with N-API under node.js.

How do I set colorBufferWriteMask from Material Inspector

Im using "colorBufferWriteMask = []" to create a box that occludes part of the scene like a clipping mask. However, Im a bit new to this and I want to know if there is a way to use Xcodes material inspector to set a geometries matierial as such?
let occlusionMaterial = SCNMaterial()
occlusionMaterial.colorBufferWriteMask = []
geometry.materials = [occlusionMaterial]
First on the bottom of Material Inspector you can see 'Write to color' with options red, blue, green and alpha ticked. Untick all of them. This creates a transparent material. Or there is 'Transparency' just under 'Settings'. Change it's mode to 'RGB Zero' and value to 1.
Now go to Node Inspector and under 'Visibility' you will see 'Rendering Order' with value 0. Set it to -1 (the idea is to set this order lower than object's that gets occluded behind it)
You can see the objects behind the node with this settings will be invisible.

Remove black border from TcolorButton

Is there anyway to remove the black border from a TColorbutton ? Delphi xe5, developing for iOSdelp
There are actually three black or gray borders.
First, add a custom stylebook to your app. The docwiki tells how to do this:
http://docwiki.embarcadero.com/RADStudio/XE5/en/Customizing_the_Design_of_a_FireMonkey_Application
Follow step #2 (Step 3 doesn't work for mobile applications.)
Open the style editor and locate ColorButtonStyle.
Expand the tree node and click on "background" in the structure.
In the object inspector locate Fill and expand that node.
Change the fill Kind to bkNone.
That removes the wide gray bordered, leaving two dark gray 1px borders.
Further down the list of properties just below Sides is Stroke.
Change it's Kind to bkNone. That removes the outer gray line.
Depending on your app you may need to also edit the color animations below the background rectangle. I did this by erasing (blanking out) the triggers since I was unable to delete the animations.
Next go the Fill component and set the stroke kind to bkNone. That removes the inner gray line.
You may also also want to set the Fill Margins to 0 so the color extends to the outside of the object. (i.e no padding now that the gray is not there.)
Gary

How to make color bar above navigator in Highstock?

I have chart showing time data. I have two points back in time which I need to "mark" in the chart.
I currently indicate these two by plotlines, but would like to show bar, with let's say green and blue bars showing the timespans (for example -13days from now with blue and -90days -> -13days with red).
I would use plotBands, but I can't specify their height and do not want to have them all over the chart.
Is there some way? I saw something about translating pixels and drawing rectangle, but wasn't able to make it work. Also - I zoom a lot in this chart.
You can use Renderer and add custom shape. In other cases, please attach mockup of your goal.
http://api.highcharts.com/highstock#Renderer

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