I am wondering if anyone could provide a simple working example of a histogram that has different background colours for different values of "x". Something that would look like the following graph:
I cannot seem to find an easy way to do this, even though it is a fairly common visual tool when using histograms in a time context.
Please study https://stackoverflow.com/help/mcve for future questions. Here in the question we see no data example, no attempt at code, no provenance for your graph.
This is reproducible:
webuse grunfeld, clear
line invest year if company == 1
twoway scatteri 0 1939 1500 1939 1500 1945 0 1945, recast(area) color(gs12) || line invest year if company == 1 , ytitle(invest) legend(order(1 "WW II") pos(11))
Steps:
Draw a line plot and decide what to highlight. It's a rectangle and you need the coordinates of the corners.
It's crucial to draw the rectangle first, as otherwise it will overwrite your line plot. Tastes and imperatives vary, but a light gray often works well.
The rectangle is drawn by specifying an "immediate" scatteri plot of the coordinates of the corners, but recasting to an area plot.
You need to reach in and fix the vertical axis title and very possibly the legend. Fine tuning: use the Graph Editor.
Optionally use plotregion(margin(zero)) to remove the default area between the axes and the plotregion.
Related
I have a data set that I receive from an outside source, and have no real control over.
The data, when plotted, shows two clumps of points with several sparse, irrelevant points. Here is a sample plot:
There is a clump of points on the left, clustered around (1, 16). This clump is actually part of a set of points that lies on (or near to) a line stretching from (1, 17.5) to (2.4, 13).
There is also an apparent curve from (1.75, 18) to (2.75, 12.5).
Finally, there are some sparse points above the second curve, around (2.5, 17).
Visually, it's not difficult to separate these groups of points. However, I need to separate these points within the data file into three groups, which I'll call Line, Curve, and Other (the Curve group is the one I actually need). I'd like to write a program that can do this reasonably well without needing to visually see the plot.
Now, I'm going to add a couple items that make this much worse. This is only a sample set of data. While the shapes of the curve and line are relatively constant from one data set to the next, the positions are not. These regions can (and do) shift, both horizontally and vertically. The only real constant is that there's a negative-slope line from the top-left to the bottom-right of the plot, an almost curve from the top-center to the bottom-right, and most of the sparse points are in the top-right corner, above the curve.
I'm on Linux, and I'm out of ideas. I can tell you the approaches that I've tried, though they have not done well.
First, I cleaned up the data set and sorted it in ascending order by x-coordinate. I thought that maybe the points were sorted in some sort of a logical way that would allow me to 'head' or 'tail' the data to achieve the desired result, but this was not the case.
I can write a code in anything (Python, Fortran, C, etc.) that removes a point if it's not within X distance of the previous point. This would be just fine, except that the scattering of the points is such that two points very near each other in x, are separated by an appreciable distance in y. It also doesn't help that the Line and Curve draw near one another for larger x-values.
I can fit a curve to a partial data set. When I sort the data by x-coordinate, for example, I can choose to only plot the first 30 points, or the last 200, or some set of 40 in the middle somewhere. That's not a problem. But the Line points tuck underneath the Curve points, which causes a problem.
If the Line points were fairly constant (which they're not), I could rotate my plot by some angle so that the Line is vertical and I can just look at the points to the right of that line, then rotate back. This may the best way to go about doing this, but in order to do that, I need to be able to isolate the linear points, which is more or less the essence of the problem.
The other idea that seems plausible to me, is to try to identify point density and split the data into separate files by those parameters. I think this is the best candidate for this problem, since it is independent of point location. However, I'm not sure how to go about doing this, especially because the Line and Curve do come quite close together for larger x-values (In the sample plot, it's x-values greater than about 2).
I know this does not exactly fall in with the request of a MWE, but I don't know how I'd go about providing a more classical MWE. If there's something else I can provide that would help, please ask. Thank you in advance.
How is it possible object can pass through ring spirte like in the image below?
Please can you help me I have no idea how can i do that.
I think you posted a incorrect image. To get the image you posted you just have to draw the red bar on top of the black ring.
I guess you want the ring on the left side to be on top and the right side to be over so it visually goes through. Well this is simply not so easy in 2D since draw order.
I have a couple of suggestion you can explore.
Always draw the ring on top of the bar but when a collision is happening you calculate where the bar overlaps and don't draw the pixels in that place. You can use a Pixmap for calculations like this. Depending on the size of your images this could be very expensive to calculate each frame.
A faster but slightly more hacky way could be to split red bar in multiple images and if a certain part of it should be overlapped by the ring draw it first otherwise draw it after the ring. Depending on what the red bar is going to look in your end product and how much possible angles the bar could have I can imagine this can be very tricky to get right.
Use 3D for this. You could have a billboard with a slight angle for the ring and have the bar locked on the distance axis at the rings center. However, on certain angles of entrance and exit you will get Z fighting since the pixels will be at the same distance from the camera. This might or might not be noticable and I have no idea how LibGDX would handle Z fighting.
I wanna add this solution :
if the object gonna pass through the ring horizontally i propose to devise sprite ring in to to sprite (sprite 1 & sprite 2)
you just have to draw sprites in that order :
Sprite1
Sprite Object
Sprite2
You can do the same if the object is gonna pass through ring vertically
PS : this solution don't work if the object is going to passs through ring both Vertically and Horizontally
Hope this was helpfull
Good luck
I created my own little 2D-Engine with DirectX (okey, should be more like a GUI in the end) and tried to create rounded edges for a simple Rectangle. Since I never done this with a graphics framework before I had no idea how to supply this.
For now, I just overlapped 5 Rectangles and 4 circles (the circles are used for the rounded edges). It does work with opaque colors but if I add alpha into the rectangles the circles are making problems. (Shown in the image below - i should have choose another colors...)
<# Open Image #>
I can't find a solution myself (I googled and whondered I found nothing about rounded edges in DirectX) and I do believe there is a much powerful and faster method doing this. So my final question is, what are the common algorythm to create a rectangle with rounded edges in Direct3D9 ?
The common way to draw rounded quads is the use of textures with an alphachannel. It's very easy and the most of the gui's uses images to achieve a specific look. If you draw only single-colored boxes it may look very generic after a while (even if they have fancy rounded corners ;) ).
But if you want to draw rounded quads directly, I would suppose to generate a custom geometry, which fits the desired area directly without overlapping (need for alphablending). In you case it would be something like this:
The more triangles you're using for the corner the smoother it will look.
I need to write some code (for a web.py webapp with a straight-HTML/JS client) that will generate a visual representation of a set of point-values. Each point has an X and Y coordinate, and the value is an integer. If I can use SVG to do this, then I can scale the image client-side with no extra code. Can I actually do this? I am concerned about a couple of things:
The points don't necessarily have any relation to each other. They aren't necessarily in a grid, nor can we say how many points are nearby, etc.
Gradients are primarily one-direction, and multiple gradients on the same shape seems to be a foreign concept.
Fills require an existing image, at which point, I'd be better off generating the entire image server-side anyway.
Objects always have a layering, even if it isn't specified, which can change how the image is rendered.
If it helps, consider a situation where we have a point surrounded by 5 others, where one of them is a bit closer than the others (exact distances and sizes can be adjusted). All six of the points have different colors (Red, Green, Blue, Cyan, Magenta, Yellow, with red in the center and Yellow being slightly closer), and the outer five points are arranged roughly in a pentagon. Note that this situation is not the only option, just a theoretically possible situation.
Can I do this with SVG, or should I render an image server-side?
EDIT: The main difficulty isn't in drawing the points, it is in filling the space between the points so that there is no whitespace, and color transitions aren't harsh/unpredictable if you know the data.
I don't entirely understand the different issues you are having with wanting to use svg. I am currently using the set up you are describing to render X-Y scatter plots and gaussian curves and found that it works great.
Regarding the last point about object layering, you have to be particularly careful when layering objects with less than 100% opacity which are different colors. The way the colors "add" depends on the order in which you add the objects to your svg drawing.
Thankfully you can use different filters to overlay the colors without blending them. Specifically I am using the FeComposite filter element. There is a good example of its usage here:
http://www.w3.org/TR/SVG/filters.html#feCompositeElement
I have this graph created with gnuplot
However the red line at the bottom seems like very straight due to the y-axis range although it is not (it should look like the blue one). How can make the range of the y-axis very fine grained (lots of ticks) so very small values of the red graph can be visible ? Hope I was clear thanks.
I can think of two possible solutions to your question.
Use a logarithmic scale with set logscale y. This would change the look of your plot quite a bit but you would still have all the data related to a single scale and it would most probably introduce a "higher resolution" to your red line.
Introduce a second y-axis like in this example.
As far as I know, it is not possible to increase the resolution only on a specific part of an axis. I think, this would lead to more confusion than it would do any good.