I don't know if its right forum. I'm posting question related to autocad. So please share link of forum (if I'm not allowed to ask it here)
How can I change point size (single point size 1/2/3) of point cloud (imported as pcg) in autocad.
POINT Command
Creates a point object
Draw menu: Point
Command line: point
Specify a point:
Points can act as nodes to which you can snap objects. You can specify a full three-dimensional location for a point. The current elevation is assumed if you omit the Z coordinate value.
The PDMODE and PDSIZE system variables control the appearance of point objects. PDMODE values 0, 2, 3, and 4 specify a figure to draw through the point. A value of 1 specifies that nothing is displayed.
Specifying the value 32, 64, or 96 selects a shape to draw around the point, in addition to the figure drawn through it:
PDSIZE controls the size of the point figures, except for PDMODE values 0 and 1. A setting of 0 generates the point at 5 percent of the drawing area height. A positive PDSIZE value specifies an absolute size for the point figures. A negative value is interpreted as a percentage of the viewport size. The size of all points is recalculated when the drawing is regenerated.
After you change PDMODE and PDSIZE, the appearance of existing points changes the next time AutoCAD regenerates the drawing.
Related
Application used: everycircuit
Example circuits used (the book icon in the left sidebar):
: "LED Array", "RC step response"
So,
the image is of a parametric plot of some quantities on vertical axis (legend indicated by #3 in image), and one quantity on horizontal axis (legend indicated by #2)
in this, there's one parameter with respect to which all values are changing (which is time)
in the plot, the trail of values is kept for some time then it is erased - the keeping behaviour helps when the system is stable, and the erasing helps a lot to declutter the plot and zoom into the new relevant area/scale when the system changes its characteristics
How to do this animation in other code based data analysis software? like python/octave/julia etc?
Animation i.e.
the values changing with change in the parameter (i.e. the normal plot),
but the trail shown for only some time (hence, non-static)
while still retaining some way to change the parameter, and see which point corresponds to that (also known as "track" the plot)
I'm showing network throughput and disk io's in a graph.
But when there is no activity. 0 get's reported.
The balloon shows me 0 but the line is not being drawn.
it looks like the grid is on top but if I turn the grid off the line still isn't there.
if I make line-thickness 2, I can see it but then the line changes thickness between 0 value and non 0 value. from 1px to 2 px.
i can't find anything in the documentation about this.
Any clue?
Unfortunately this is a limitation with the library as it doesn't draw lines outside of the plot area so the line will be clipped at the edges as you've noticed. Setting the lineThickness to a larger number like you already did along with setting the valueAxis' zeroGridAlpha property to zero will improve it slightly, but your best bet is setting a small negative minimum in your valueAxis so that the zero line is clearly visible. You can combine this with setting showFirstLabel to false to hide the first negative value in your axis.
Demo
On a shape from a logical image, I am trying to extract the field of view from any point inside the shape on matlab :
I tried something involving to test each line going through the point but it is really really long.(I hope to do it for each points of the shape or at least each point of it's contour wich is quite a few times)
I think a faster method would be working iteratively by the expansion of a disk from the considered point but I am not sure how to do it.
How can I find this field of view in an efficient way?
Any ideas or solution would be appreciated, thanks.
Here is a possible approach (the principle behind the function I wrote, available on Matlab Central):
I created this test image and an arbitrary point of view:
testscene=zeros(500);
testscene(80:120,80:120)=1;
testscene(200:250,400:450)=1;
testscene(380:450,200:270)=1;
viewpoint=[250, 300];
imsize=size(testscene); % checks the size of the image
It looks like this (the circle marks the view point I chose):
The next line computes the longest distance to the edge of the image from the viewpoint:
maxdist=max([norm(viewpoint), norm(viewpoint-[1 imsize(2)]), norm(viewpoint-[imsize(1) 1]), norm(viewpoint-imsize)]);
angles=1:360; % use smaller increment to increase resolution
Then generate a set of points uniformly distributed around the viewpoint.:
endpoints=bsxfun(#plus, maxdist*[cosd(angles)' sind(angles)'], viewpoint);
for k=1:numel(angles)
[CX,CY,C] = improfile(testscene,[viewpoint(1), endpoints(k,1)],[viewpoint(2), endpoints(k,2)]);
idx=find(C);
intersec(k,:)=[CX(idx(1)), CY(idx(1))];
end
What this does is drawing lines from the view point to each directions specified in the array angles and look for the position of the intersection with an obstacle or the edge of the image.
This should help visualizing the process:
Finally, let's use the built-in roipoly function to create a binary mask from a set of coordinates:
FieldofView = roipoly(testscene,intersec(:,1),intersec(:,2));
Here is how it looks like (obstacles in white, visible field in gray, viewpoint in red):
I have a system that collects statistics from servers for every 5 minutes and displays a line graph using dhtmlxChart as shown below. I want to add points to the graph when there are significant change of the trend in the statistics, for example when the line graph looks like saw teeth from 00:00 to 06:00 in the image below, the graph will display square points at the periodical high and low values. As you can see, my existing algorithm does not work well.
interate over each point:
if last visible point not defined then:
set current point as visible
store current point as last visible point
else:
compare absolute difference between last visible point and current point
if difference exceeds threshold or current point is the last point then:
set current point as visible
store current point as last visible point
What would be a correct algorithm to determine the visible points in the line graph?
There is no way to add points, but you can redraw the chart using updated data source.
Look at the samples from this theme
You can use your "line" chart type
I'm searching for an certain object in my photograph:
Object: Outline of a rectangle with an X in the middle. It looks like a rectangular checkbox. That's all. So, no fill, just lines. The rectangle will have the same ratios of length to width but it could be any size or any rotation in the photograph.
I've looked a whole bunch of image recognition approaches. But I'm trying to determine the best for this specific task. Most importantly, the object is made of lines and is not a filled shape. Also, there is no perspective distortion, so the rectangular object will always have right angles in the photograph.
Any ideas? I'm hoping for something that I can implement fairly easily.
Thanks all.
You could try using a corner detector (e.g. Harris) to find the corners of the box, the ends and the intersection of the X. That simplifies the problem to finding points in the right configuration.
Edit (response to comment):
I'm assuming you can find the corner points in your image, the 4 corners of the rectangle, the 4 line endings of the X and the center of the X, plus a few other corners in the image due to noise or objects in the background. That simplifies the problem to finding a set of 9 points in the right configuration, out of a given set of points.
My first try would be to look at each corner point A. Then I'd iterate over the points B close to A. Now if I assume that (e.g.) A is the upper left corner of the rectangle and B is the lower right corner, I can easily calculate, where I would expect the other corner points to be in the image. I'd use some nearest-neighbor search (or a library like FLANN) to see if there are corners where I'd expect them. If I can find a set of points that matches these expected positions, I know where the symbol would be, if it is present in the image.
You have to try if that is good enough for your application. If you have too many false positives (sets of corners of other objects that accidentially form a rectangle + X), you could check if there are lines (i.e. high contrast in the right direction) where you would expect them. And you could check if there is low contrast where there are no lines in the pattern. This should be relatively straightforward once you know the points in the image that correspond to the corners/line endings in the object you're looking for.
I'd suggest the Generalized Hough Transform. It seems you have a fairly simple, fixed shape. The generalized Hough transform should be able to detect that shape at any rotation or scale in the image. You many need to threshold the original image, or pre-process it in some way for this method to be useful though.
You can use local features to identify the object in image. Feature detection wiki
For example, you can calculate features on some referent image which contains only the object you're looking for and save the results, let's say, to a plain text file. After that you can search for the object just by comparing newly calculated features (on images with some complex scenes containing the object) with the referent ones.
Here's some good resource on local features:
Local Invariant Feature Detectors: A Survey