I am using MATLAB 2018b and using rlocus function to plot some function. In the figure I have to select some data points based on specific values. But When I zoom in and select a data point it remains in the exact position. But when I try to move the figure with pan option or zoom out the selected point moves relatively. I want these data points to remain in that specific position. But I can't stop this relative scaling of axis. My code is:
clear all
close all
clc
Gs=zpk([-8],[-3 -6 -10],1)
rlocus(Gs)
Related
I'm trying to build a stock chart with zooming functionality using D3.js
I'm looking to start with this example here and attempt to make the zoom feel more natural for a stock chart. A perfect example is this. So the difference as far as I understand is that zoomng and panning are both locked on the Y-axis, and the only way the Y-axis moves is to autmatically fill the price range of the currently visible data.
Another noticeable difference is that zooming does not zoom into the current position of the mouse like it does in the first example.
How can the example be adjusted to work more closely as the other chart? What is the pertitent code, how should it be changed?
Setting the zoom behaviour to not affect the y-axis is simple: just don't attach your y-scale to the zoom behaviour.
In the sample code you linked to, the zoom functionality is added in this line:
this.plot.call(d3.behavior.zoom()
.x(this.x)
.y(this.y)
.on("zoom", this.redraw() )
);
That creates a zoom behaviour object/function, links it to the graphs x and y scales, and tells it to call the function returned by this.redraw() after every zoom event. The zoom behaviour automatically changes the domain of the scales on zoom, and then the redraw function uses the modified zoom. If you don't give it a y scale to modify, then zooming won't affect the y domain.
Getting the y scale to automatically adjust to the given extent of the data is a little trickier. However, remember that the zoom behaviour will have automatically adjusted the domain of the x scale to represent the extent of visible data horizontally. You'll then have to get the corresponding slice of your data array and figure out the extent of y values from it, set your y domain accordingly, and then call the redraw function (remembering that this.redraw() just returns the redraw function, to call it within another function you'll need to use this.redraw()() ).
To have the zoom be independent of the mouse position, set a center point for the zoom behaviour.
I intend to draw maps using d3.js and geoJson.
I need to plot circles on this map.These circles when hovered should get bigger and display some data inside that.
Also,i need to create a time line scale which will increase and decrease the circles in the map based on the data for that particular time frame.
I am able to draw map with the help of geo JSON file but the problem is how to plot the circles such that when map is moved in the canvass the circle remains at same position inside the map.I mean the circles should be relative to map not relative to canvass.
Secondly I am not able to understand how the coordinate system of maps work.
Any help Please..
I am learning d3js and trying to incorporate zooming/panning features on a graph, however on the initial zoom event it jumps to a random spot and zooms in. After that, the zooming and panning work as expected. Why is the initial event moving the starting point and adjusting the scale oddly?
Code and example here: bl.ocks.org/dbaileychess/7570631
This is because the zoom behaviour is attached to a different element than the one you're zooming. It determines the position of the mouse cursor relative to its own position and passes that information to the callback. If you're zooming a different element, the relative coordinates are no longer correct.
To fix, add the offset between the elements that the zoom behaviour is attached to and the elements you're zooming to the translation. This question has come up a number of times already, see e.g. here.
I have a situation that I'm not realy sure how I can handle. I have an openGl object of about 20k vertices, and I need to offer the user the possibility to select any one of these vertices (let's say with a smallest margin of error possible). Now here is what I want to do in order to do this:
Next to the 3D canvas of the object, I also offer the user 3 'slices' done by the planes x=0; y=0 and z=0. Say for the simplest example for a sphere these would be 3 circles, correponding to 'cutting' out one of the dimensions. Now let's take the z=0 one for the purpose of the example. When the user clicks on a point say (x_circle, y_circle) i would like to get the actual point in the 3d representation where he clicked. The z would be 0 of course but I can't figure out a way to get the x and y. I can easily translate that (x_circle, y_circle) -> (x_screen, y_screen) which would have the same result as a click on the canvas at those coordinates, but I need to find a way to translate that into the (x, y, 0) coordinate in 3D view.
The same thing would need to be done with x=0, y=0 but I think if I can understand/implement a way for z=0 I can just apply more or less the same solution with an added rotation over something. If anyone can help with any examples/code or even math behind this it would help a lot because at the moment I'm not really sure how to proceed.
When the user clicks, you can render the vertices using GL.POINTS (with a certain size, if you like) to an off-screen buffer using a shader that renders each vertex' index into RGBA. Then you read back the pixel on the mouse position and see what index it is.
So I am using jqPlot to display distance (y-axis) over time (x-axis) in a simple line graph.
However, while I have actual distances as the underlying data used to position the points, I'm not interested in displaying those distances on the y-axis.
Instead, there are a series of landmarks at given distances, that I want to appear on the y-axis as a 'tick' next to the appropriate point for the distance to that landmark. That way the line appears to "pass" each landmark as it travels upward.
Currently I'm "faking" this by hiding the ticks and putting a manually-created series of labels next to the graph. This works well enough, but I had to disable vertical zooming because if the user chose to zoom in, the labels would not match up with the actual distances. My users would really like to zoom in vertically, however, and I want to allow them to.
Therefore, does anyone know of a way (a plugin or similar) that would allow me to associate custom labels with given tick marks in jqPlot, that will match up nicely and respond to zooming? It would be necessary to hide some of the landmarks if the graph is zoomed out too much, so that would have to be a feature.
Alternatively, if someone knows of a "zoom event" that passes in the min and max y values, I could probably recreate my manual labels with that data, so let me know if you know of a way to get that information. I haven't been able to find one.
I would need to see a bit of your code to customize it to the distance but to start with you could label the ticks and it will display over the size of the chart.
axes:{yaxis:{ticks:['DiscanceA','DiscanceB', 'DiscanceC', 'DiscanceD', 'DiscanceE'],
renderer: $.jqplot.CategoryAxisRenderer,},
Let me know how it goes and if you have any code lets see it!