Search Results

Search found 103 results on 5 pages for 'interpolate'.

Page 3/5 | < Previous Page | 1 2 3 4 5  | Next Page >

  • Is a function plotter a legitimate use of eval() in JavaScript?

    - by moose
    From PHP development I know that eval is evil and I've recently read What constitutes “Proper use” of the javascript Eval feature? and Don't be eval. The only proper use of eval I've read is Ajax. I'm currently developing a visualization tool that lets users see how polynomials can interpolate functions: Example Code on GitHub I use eval for evaluation of arbitrary functions. Is this a legitimate use of eval? How could I get rid of eval? I want the user to be able to execute any function of the following forms: a x^i with a,i in R sin, cos, tan b^x with b in R any combination that you can get by adding (e.g. x^2 + x^3 + sin(x)), multiplying (e.g. sin(x)*x^2) or inserting (e.g. sin(x^2))

    Read the article

  • Smooth animation using MatrixTransform?

    - by Mattias Konradsson
    I'm trying to do an Matrix animation where I both scale and transpose a canvas at the same time. The only approach I found was using a MatrixTransform and MatrixAnimationUsingKeyFrames. Since there doesnt seem to be any interpolation for matrices built in (only for path/rotate) it seems the only choice is to try and build the interpolation and DiscreteMatrixKeyFrame's yourself. I did a basic implementation of this but it isnt exactly smooth and I'm not sure if this is the best way and how to handle framerates etc. Anyone have suggestions for improvement? Here's the code: MatrixAnimationUsingKeyFrames anim = new MatrixAnimationUsingKeyFrames(); int duration = 1; anim.KeyFrames = Interpolate(new Point(0, 0), centerPoint, 1, factor,100,duration); this.matrixTransform.BeginAnimation(MatrixTransform.MatrixProperty, anim,HandoffBehavior.Compose); public MatrixKeyFrameCollection Interpolate(Point startPoint, Point endPoint, double startScale, double endScale, double framerate,double duration) { MatrixKeyFrameCollection keyframes = new MatrixKeyFrameCollection(); double steps = duration * framerate; double milliSeconds = 1000 / framerate; double timeCounter = 0; double diffX = Math.Abs(startPoint.X- endPoint.X); double xStep = diffX / steps; double diffY = Math.Abs(startPoint.Y - endPoint.Y); double yStep = diffY / steps; double diffScale= Math.Abs(startScale- endScale); double scaleStep = diffScale / steps; if (endPoint.Y < startPoint.Y) { yStep = -yStep; } if (endPoint.X < startPoint.X) { xStep = -xStep; } if (endScale < startScale) { scaleStep = -scaleStep; } Point currentPoint = new Point(); double currentScale = startScale; for (int i = 0; i < steps; i++) { keyframes.Add(new DiscreteMatrixKeyFrame(new Matrix(currentScale, 0, 0, currentScale, currentPoint.X, currentPoint.Y), KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(timeCounter)))); currentPoint.X += xStep; currentPoint.Y += yStep; currentScale += scaleStep; timeCounter += milliSeconds; } keyframes.Add(new DiscreteMatrixKeyFrame(new Matrix(endScale, 0, 0, endScale, endPoint.X, endPoint.Y), KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0)))); return keyframes; }

    Read the article

  • Interpolating in HSV color space

    - by user146780
    I have an HSV color A at 3/10 of a line and HSV color B at 9/10 of a line. I'm making multistep gradients and for example if I wanted to find the color at 6/10ths of a line, how could I interpolate these HSV colors? I'm firmiliar with the technique for rgb but not HSV. I should also add that my HSV's are integers H(0,360) S(0,100) V(0,100). Thanks

    Read the article

  • How to Create a Duotone Interpolation Color in GDI+ (.NET)?

    - by Otaku
    I have two colors that I need to linearly interpolate to create a duotone color based of another color's luminance value. Dim clr1 = Color.Black Dim clr2 = Color.FromArgb(224, 255, 165) Dim lum = Color.FromArgb(226, 189, 136).GetBrightness 'lum = 0.71 I know the result of this should be R=171, G=192, B=125, but I can't figure out how to do this. I've searched through SO quite a bit and all over Google, but have not discovered a way to produce this result. Can anyone help?

    Read the article

  • Interpolation not working on Rails generator

    - by Tom
    For some reason the code I have included below does not interpolate the variables into the template. It simply copies the file over verbatim. I cannot figure out why. https://gist.github.com/60484f7b57b06b6eb3e3 The Rails version is 2.3.4. Thanks in advance!

    Read the article

  • Movement prediction for non-shooters

    - by ShadowChaser
    I'm working on an isometric 2D game with moderate-scale multiplayer, approximately 20-30 players connected at once to a persistent server. I've had some difficulty getting a good movement prediction implementation in place. Physics/Movement The game doesn't have a true physics implementation, but uses the basic principles to implement movement. Rather than continually polling input, state changes (ie/ mouse down/up/move events) are used to change the state of the character entity the player is controlling. The player's direction (ie/ north-east) is combined with a constant speed and turned into a true 3D vector - the entity's velocity. In the main game loop, "Update" is called before "Draw". The update logic triggers a "physics update task" that tracks all entities with a non-zero velocity uses very basic integration to change the entities position. For example: entity.Position += entity.Velocity.Scale(ElapsedTime.Seconds) (where "Seconds" is a floating point value, but the same approach would work for millisecond integer values). The key point is that no interpolation is used for movement - the rudimentary physics engine has no concept of a "previous state" or "current state", only a position and velocity. State Change and Update Packets When the velocity of the character entity the player is controlling changes, a "move avatar" packet is sent to the server containing the entity's action type (stand, walk, run), direction (north-east), and current position. This is different from how 3D first person games work. In a 3D game the velocity (direction) can change frame to frame as the player moves around. Sending every state change would effectively transmit a packet per frame, which would be too expensive. Instead, 3D games seem to ignore state changes and send "state update" packets on a fixed interval - say, every 80-150ms. Since speed and direction updates occur much less frequently in my game, I can get away with sending every state change. Although all of the physics simulations occur at the same speed and are deterministic, latency is still an issue. For that reason, I send out routine position update packets (similar to a 3D game) but much less frequently - right now every 250ms, but I suspect with good prediction I can easily boost it towards 500ms. The biggest problem is that I've now deviated from the norm - all other documentation, guides, and samples online send routine updates and interpolate between the two states. It seems incompatible with my architecture, and I need to come up with a better movement prediction algorithm that is closer to a (very basic) "networked physics" architecture. The server then receives the packet and determines the players speed from it's movement type based on a script (Is the player able to run? Get the player's running speed). Once it has the speed, it combines it with the direction to get a vector - the entity's velocity. Some cheat detection and basic validation occurs, and the entity on the server side is updated with the current velocity, direction, and position. Basic throttling is also performed to prevent players from flooding the server with movement requests. After updating its own entity, the server broadcasts an "avatar position update" packet to all other players within range. The position update packet is used to update the client side physics simulations (world state) of the remote clients and perform prediction and lag compensation. Prediction and Lag Compensation As mentioned above, clients are authoritative for their own position. Except in cases of cheating or anomalies, the client's avatar will never be repositioned by the server. No extrapolation ("move now and correct later") is required for the client's avatar - what the player sees is correct. However, some sort of extrapolation or interpolation is required for all remote entities that are moving. Some sort of prediction and/or lag-compensation is clearly required within the client's local simulation / physics engine. Problems I've been struggling with various algorithms, and have a number of questions and problems: Should I be extrapolating, interpolating, or both? My "gut feeling" is that I should be using pure extrapolation based on velocity. State change is received by the client, client computes a "predicted" velocity that compensates for lag, and the regular physics system does the rest. However, it feels at odds to all other sample code and articles - they all seem to store a number of states and perform interpolation without a physics engine. When a packet arrives, I've tried interpolating the packet's position with the packet's velocity over a fixed time period (say, 200ms). I then take the difference between the interpolated position and the current "error" position to compute a new vector and place that on the entity instead of the velocity that was sent. However, the assumption is that another packet will arrive in that time interval, and it's incredibly difficult to "guess" when the next packet will arrive - especially since they don't all arrive on fixed intervals (ie/ state changes as well). Is the concept fundamentally flawed, or is it correct but needs some fixes / adjustments? What happens when a remote player stops? I can immediately stop the entity, but it will be positioned in the "wrong" spot until it moves again. If I estimate a vector or try to interpolate, I have an issue because I don't store the previous state - the physics engine has no way to say "you need to stop after you reach position X". It simply understands a velocity, nothing more complex. I'm reluctant to add the "packet movement state" information to the entities or physics engine, since it violates basic design principles and bleeds network code across the rest of the game engine. What should happen when entities collide? There are three scenarios - the controlling player collides locally, two entities collide on the server during a position update, or a remote entity update collides on the local client. In all cases I'm uncertain how to handle the collision - aside from cheating, both states are "correct" but at different time periods. In the case of a remote entity it doesn't make sense to draw it walking through a wall, so I perform collision detection on the local client and cause it to "stop". Based on point #2 above, I might compute a "corrected vector" that continually tries to move the entity "through the wall" which will never succeed - the remote avatar is stuck there until the error gets too high and it "snaps" into position. How do games work around this?

    Read the article

  • Get sessions' remote IP from Teamviewer log file

    - by etuardu
    I'd like to know who has logged in to my machine and when. I have two TeamViewer log files: Connections_incoming.txt and TeamViewer7_Logfile.log. The first one is quite plain and lists, as its name says, the incoming connections to the machine, reporting the local name of the remote host, login time, logout time, and some ids. e.g.: 173274362 MYLAPTOP 20-02-2012 17:32:16 20-02-2012 17:50:42 Master RemoteControl {C5AAE483-ED0B-54B8-9235-7AE597CAD342} This is almost all what I need, but unfortunately no remote IP address is reported here, so I checked for IPs in TeamViewer7_Logfile.log but it is really messy. It indeed contains some IP addresses but I can't understand which one is bound with the items in the first log file. Is there a way to interpolate the two logs to get what I need? Should I search the second file for some particular text? What do you suggest?

    Read the article

  • Excel trendline accuracy

    - by Rook
    This is a problem I have every once in a while, and it annoys me tremendously, beacuse I have always to recheck every trendline I get. An example: r L (mm) 30,00 97,0 60,00 103,2 90,00 106,0 110,00 101,0 125,00 88,0 140,00 62,0 148,00 36,7 152,50 17,0 Upon drawing a trendline (using 3rd order polynomial regression type) with r on the x axis, and L on the y one, Excel will give the formula y = -0,0002x³ + 0,0341x² - 1,8979x + 128,73 with R² = 0,994. If I interpolate values using that formula for the same values of r as the ones the formula was derived from, I get r y (mm) 30,00 97,083 60,00 94,416 90,00 88,329 110,00 66,371 125,00 33,68 140,00 -17,416 148,00 -53,5912 152,50 -76,97725 which are quite different? Why does this happen? What is the reason for it?

    Read the article

  • Glenn Fiedler's fixed timestep with fake threads

    - by kaoD
    I've implemented Glenn Fiedler's Fix Your Timestep! quite a few times in single-threaded games. Now I'm facing a different situation: I'm trying to do this in JavaScript. I know JS is single-threaded, but I plan on using requestAnimationFrame for the rendering part. This leaves me with two independent fake threads: simulation and rendering (I suppose requestAnimationFrame isn't really threaded, is it? I don't think so, it would BREAK JS.) Timing in these threads is independent too: dt for simulation and render is not the same. If I'm not mistaken, simulation should be up to Fiedler's while loop end. After the while loop, accumulator < dt so I'm left with some unspent time (dt) in the simulation thread. The problem comes in the draw/interpolation phase: const double alpha = accumulator / dt; State state = currentState*alpha + previousState * ( 1.0 - alpha ); render( state ); In my render callback, I have the current timestamp to which I can subtract the last-simulated-in-physics-timestamp to have a dt for the current frame. Should I just forget about this dt and draw using the physics thread's dt? It seems weird, since, well, I want to interpolate for the unspent time between simulation and render too, right? Of course, I want simulation and rendering to be completely independent, but I can't get around the fact that in Glenn's implementation the renderer produces time and the simulation consumes it in discrete dt sized chunks. A similar question was asked in Semi Fixed-timestep ported to javascript but the question doesn't really get to the point, and answers there point to removing physics from the render thread (which is what I'm trying to do) or just keeping physics in the render callback too (which is what I'm trying to avoid.)

    Read the article

  • Rendering different materials in a voxel terrain

    - by MaelmDev
    Each voxel datapoint in my terrain model is made up of two properties: density and material type. Each is stored as an unsigned integer value (but the density is interpreted as a decimal value between 0 and 1). My current idea for rendering these different materials on the terrain mesh is to store eleven extra attributes in each vertex: six material values corresponding to the materials of the voxels that the vertices lie between, three decimal values that correspond to the interpolation each vertex has between each voxel, and two decimal values that are used to determine where the fragment lies on the triangle. The material and interpolation attributes are the exact same for each vertex in the triangle. The fragment shader samples each texture that corresponds to each material and then uses the aforementioned couple of decimal values to interpolate between these samples and obtain the final textured color of the fragment. It should work fine, but it seems like a big memory hog. I won't be able to reuse vertices in the mesh with indexing, and each vertex will have a lot of data associated with it. It also seems pretty slow. What are some ways to improve or replace this technique for drawing materials on a voxel terrain mesh?

    Read the article

  • Handling early/late/dropped packets for interpolation in a 3D multiplayer game

    - by Ben Cracknell
    I'm working on a multiplayer game that for the purposes of this question, is most similar to Team Fortress. Each network data packet will contain the 3D position of the target moving object. (this object could be another player) The packets are sent on a fixed interval, and linear interpolation will be used to smooth the transition between packets. Under normal circumstances, interpolation will occur between the second-to-last packet, and the last packet received. The linear interpolation algorithm is the same as this post: Interpolating positions in a multiplayer game I have the same issue as in that post, but the answers don't seem like they will work in my situation. Consider the following scenario: Normal packet timing, everything is okay The next expected packet is late. That's okay, we'll just extrapolate based on previous positions The late packet eventually arrives with corrections to our extrapolation. Now what do we do with its information? The answers on the above post suggest we should just interpolate to this new packet's position, but that would not work at all. If we have already extrapolated past that point in time, moving back would cause rubber-banding. The issue is similar in the case of an early or dropped packet. So I believe what I am looking for is some way to smoothly deal with new information in an ongoing interpolation/extrapolation process. Since I might be moving on to quadratic or even cubic interpolation, it would be great if the same solutiuon could be applied to those as well.

    Read the article

  • Multiplayer Network Game - Interpolation and Frame Rate

    - by J.C.
    Consider the following scenario: Let's say, for sake of example and simplicity, that you have an authoritative game server that sends state to its clients every 45ms. The clients are interpolating state with an interpolation delay of 100 ms. Finally, the clients are rendering a new frame every 15ms. When state is updated on the client, the client time is set from the incoming state update. Each time a frame renders, we take the render time (client time - interpolation delay) and identify a previous and target state to interpolate from. To calculate the interpolation amount/factor, we take the difference of the render time and previous state time and divide by the difference of the target state and previous state times: var factor = ((renderTime - previousStateTime) / (targetStateTime - previousStateTime)) Problem: In the example above, we are effectively displaying the same interpolated state for 3 frames before we collected the next server update and a new client (render) time is set. The rendering is mostly smooth, but there is a dash of jaggedness to it. Question: Given the example above, I'd like to think that the interpolation amount/factor should increase with each frame render to smooth out the movement. Should this be considered and, if so, what is the best way to achieve this given the information from above?

    Read the article

  • Colored Collision Detection

    - by tugrul büyükisik
    Several years ago, i made a fast collision detection for 2D, it was just checking a bullets front-pixel's color to check if it were to hit something. Lets say the target rgb color is (124,200,255) then it just checks for that color. After the collision detection, it paints the target with appropriate picture. So, collision detection is made in background without drawing but then painted and drawed. How can i do this in 3D? Because, a vertex is not just exist like a 2D picture's pixel. I looked at some java3D and other programs and understood that 3D world is made of objects. Not just pictures. Is there a program that truly fills the world with vertices ? But it could be needing terabytes of ram even more. Do you know an easy way to interpolate the color of a vertex in java3D or similar program? Note: for a rgb color-identifier, i can make 255*255*255 different 2D objects in background.

    Read the article

  • What sort of data should be sent for mouse-based movement in a multiplayer game?

    - by Daniel
    I'm new to the Multiplayer Rodeo here so please bear with me... I am just getting started and I'm trying to figure out how to deal with movement. I've looked at the question Best way to implement mouse-based movement in MMOG which gives me a pretty good idea, but I'm still struggling with what kind of data should be sent to the server. If a player is on position [x:0, y:0] and I click with the mouse on [x:40, y:40] to start movement, what information should I send to the server? Should I calculate the position based on velocity on client side and just send the expected location? Or should I send current location and velocity and direction? When the server is updating the clients on the players' whereabouts, should the position be sent only, and the clients expected to interpolate/predict movement, or can the direction sent from the client (instead of just coordinates) be used. My concern(or confusion) is regarding the ping/lag frequency of data update and use of a predictive algorithm, as I'd like the movement to be smooth even with a high latency, and prevent ability to cheat(though that's not the top priority).

    Read the article

  • How to perform game object smoothing in multiplayer games

    - by spaceOwl
    We're developing an infrastructure to support multiplayer games for our game engine. In simple terms, each client (player) engine sends some pieces of data regarding the relevant game objects at a given time interval. On the receiving end, we step the incoming data to current time (to compensate for latency), followed by a smoothing step (which is the subject of this question). I was wondering how smoothing should be performed ? Currently the algorithm is similar to this: Receive incoming state for an object (position, velocity, acceleration, rotation, custom data like visual properties, etc). Calculate a diff between local object position and the position we have after previous prediction steps. If diff doesn't exceed some threshold value, start a smoothing step: Mark the object's CURRENT POSITION and the TARGET POSITION. Linear interpolate between these values for 0.3 seconds. I wonder if this scheme is any good, or if there is any other common implementation or algorithm that should be used? (For example - should i only smooth out the position? or other values, such as speed, etc) any help will be appreciated.

    Read the article

  • Interpolating 2d data that is piecewise constant on faces

    - by celil
    I have an irregular mesh which is described by two variables - a faces array that stores the indices of the vertices that constitute each face, and a verts array that stores the coordinates of each vertex. I also have a function that is assumed to be piecewise constant over each face, and it is stored in the form of an array of values per face. I am looking for a way to construct a function f from this data. Something along the following lines: faces = [[0,1,2], [1,2,3], [2,3,4] ...] verts = [[0,0], [0,1], [1,0], [1,1],....] vals = [0.0, 1.0, 0.5, 3.0,....] f = interpolate(faces, verts, vals) f(0.2, 0.2) = 0.0 # point inside face [0,1,2] f(0.6, 0.6) = 1.0 # point inside face [1,2,3] The manual way of evaluating f(x,y) would be to find the corresponding face that the point x,y lies in, and return the value that is stored in that face. Is there a function that already implements this in scipy (or in matlab)?

    Read the article

  • D3.js binding an object to data and appending for each key

    - by frshca
    I'm a D3.js newbie and I'm learning how to play around with data. Let's say I have an object with names as keys, and each key has an array of numbers like this: var userdata = { 'John' : [0, 1, 3, 9, 8, 7], 'Harry': [0, 10, 7, 1, 1, 11], 'Steve': [3, 1, 4, 4, 4, 17], 'Adam' : [4, 77, 2, 13, 11, 13] }; For each user, I would like to append an SVG object and then plot the line with the array of values for that user. So here is my assumption of how that would look based on tutorials, but I know it is incorrect. This is to show my limited knowledge and give better understanding of what I'm doing: First I should create the line var line = d3.svg.line().interpolate('basis'); Then I want to bind the data to my body and append an svg element for each key: d3.select('body') .selectAll('svg') .data(userdata) .enter() .append('svg') .append(line) .x(function(d, i) { return i; }) .y(function(d) { return d[i]; }); So am I close??

    Read the article

  • Huge dataset point in polygon in .net (collision detection)

    - by Rickard Liljeberg
    I have a pretty big mesh with polygons, usually triangles but sometimes rectangles. Each point in my mesh has a value (value has nothing to do with coordinates). Now I am creating a second mesh in the same coordinate-space as the old mesh. I now want to interpolate out values for all points (vertices) in the new mesh using the values from the old mesh. Now I could loop each polygon in the new mesh and detect which old vertices are in each polygon by making 2d collision detection (altho even this I don't get to function properly so if anyone has simple and fast code for 2d collision detection (triangle is enough) I would gladly see it). However to my main point again. looping each old vertice for each new polygon seems less than efficient. is there a better way?

    Read the article

  • Interpolating 1D Gaussian into 2D Gaussian

    - by Drazick
    Let's say I have a 1D Gaussian function. Its length is 600 for that matter. I want to Interpolate it into 2D Gaussian of the size 600 X 600. This is the code I wrote (OTFx is the Gaussian Function, OTF - 2d Interpolated Function): [x, y] = meshgrid([-300:299], [-300:299]); r = sqrt((x .^ 2) + (y .^ 2)); OTF = interp1([-300:299], OTFx, r(:), 'spline'); OTF = reshape(OTF, [600, 600]); The problem is I get Overshoot at the end: How can I prevent it? Is there better Interpolating algorithm for Monotonic Descending Functions?

    Read the article

  • Flipping issue when interpolating Rotations using Quaternions

    - by uhuu
    I use slerp to interpolate between two quaternions representing rotations. The resulting rotation is then extracted as Euler angles to be fed into a graphics lib. This kind of works, but I have the following problem; when rotating around two (one works just fine) axes in the direction of the green arrow as shown in the left frame here the rotation soon jumps around to rotate from the opposite site to the opposite visual direction, as indicated by the red arrow in the right frame. This may be logical from a mathematical perspective (although not to me), but it is undesired. How could I achieve an interpolation with no visual flipping and changing of directions when rotating around more than one axis, following the green arrow at all times until the interpolation is complete? Thanks in advance.

    Read the article

  • creating a color coded time chart using colorbar and colormaps in python

    - by Rusty
    I'm trying to make a time tracking chart based on a daily time tracking file that I used. I wrote code that crawls through my files and generates a few lists. endTimes is a list of times that a particular activity ends in minutes going from 0 at midnight the first day of the month to however many minutes are in a month. labels is a list of labels for the times listed in endTimes. It is one shorter than endtimes since the trackers don't have any data about before 0 minute. Most labels are repeats. categories contains every unique value of labels in order of how well I regard that time. I want to create a colorbar or a stack of colorbars (1 for eachday) that will depict how I spend my time for a month and put a color associated with each label. Each value in categories will have a color associated. More blue for more good. More red for more bad. It is already in order for the jet colormap to be right, but I need to get desecrate color values evenly spaced out for each value in categories. Then I figure the next step would be to convert that to a listed colormap to use for the colorbar based on how the labels associated with the categories. I think this is the right way to do it, but I am not sure. I am not sure how to associate the labels with color values. Here is the last part of my code so far. I found one function to make a discrete colormaps. It does, but it isn't what I am looking for and I am not sure what is happening. Thanks for the help! # now I need to develop the graph import numpy as np from matplotlib import pyplot,mpl import matplotlib from scipy import interpolate from scipy import * def contains(thelist,name): # checks if the current list of categories contains the one just read for val in thelist: if val == name: return True return False def getCategories(lastFile): ''' must determine the colors to use I would like to make a gradient so that the better the task, the closer to blue bad labels will recieve colors closer to blue read the last file given for the information on how I feel the order should be then just keep them in the order of how good they are in the tracker use a color range and develop discrete values for each category by evenly spacing them out any time not found should assume to be sleep sleep should be white ''' tracker = open(lastFile+'.txt') # open the last file # find all the categories categories = [] for line in tracker: pos = line.find(':') # does it have a : or a ? if pos==-1: pos=line.find('?') if pos != -1: # ignore if no : or ? name = line[0:pos].strip() # split at the : or ? if contains(categories,name)==False: # if the category is new categories.append(name) # make a new one return categories # find good values in order of last day newlabels=[] for val in getCategories(lastDay): if contains(labels,val): newlabels.append(val) categories=newlabels # convert discrete colormap to listed colormap python for ii,val in enumerate(labels): if contains(categories,val)==False: labels[ii]='sleep' # create a figure fig = pyplot.figure() axes = [] for x in range(endTimes[-1]%(24*60)): ax = fig.add_axes([0.05, 0.65, 0.9, 0.15]) axes.append(ax) # figure out the colors to use # stole this function to make a discrete colormap # http://www.scipy.org/Cookbook/Matplotlib/ColormapTransformations def cmap_discretize(cmap, N): """Return a discrete colormap from the continuous colormap cmap. cmap: colormap instance, eg. cm.jet. N: Number of colors. Example x = resize(arange(100), (5,100)) djet = cmap_discretize(cm.jet, 5) imshow(x, cmap=djet) """ cdict = cmap._segmentdata.copy() # N colors colors_i = np.linspace(0,1.,N) # N+1 indices indices = np.linspace(0,1.,N+1) for key in ('red','green','blue'): # Find the N colors D = np.array(cdict[key]) I = interpolate.interp1d(D[:,0], D[:,1]) colors = I(colors_i) # Place these colors at the correct indices. A = zeros((N+1,3), float) A[:,0] = indices A[1:,1] = colors A[:-1,2] = colors # Create a tuple for the dictionary. L = [] for l in A: L.append(tuple(l)) cdict[key] = tuple(L) # Return colormap object. return matplotlib.colors.LinearSegmentedColormap('colormap',cdict,1024) # jet colormap goes from blue to red (good to bad) cmap = cmap_discretize(mpl.cm.jet, len(categories)) cmap.set_over('0.25') cmap.set_under('0.75') #norm = mpl.colors.Normalize(endTimes,cmap.N) print endTimes print labels # make a color list by matching labels to a picture #norm = mpl.colors.ListedColormap(colorList) cb1 = mpl.colorbar.ColorbarBase(axes[0],cmap=cmap ,orientation='horizontal' ,boundaries=endTimes ,ticks=endTimes ,spacing='proportional') pyplot.show()

    Read the article

  • SciPy interp1d results are different than MatLab interp1

    - by LMO
    I'm converting a MatLab program to Python, and I'm having problems understanding why scipy.interpolate.interp1d is giving different results than MatLab interp1. In MatLab the usage is slightly different: yi = interp1(x,Y,xi,'cubic') SciPy: f = interp1d(x,Y,kind='cubic') yi = f(xi) For a trivial example the results are the same: MatLab: interp1([0 1 2 3 4], [0 1 2 3 4],[1.5 2.5 3.5],'cubic') 1.5000 2.5000 3.5000 Python: interp1d([1,2,3,4],[1,2,3,4],kind='cubic')([1.5,2.5,3.5]) array([ 1.5, 2.5, 3.5]) But for a real-world example they are not the same: x = 0.0000e+000 2.1333e+001 3.2000e+001 1.6000e+004 2.1333e+004 2.3994e+004 Y = -6 -6 20 20 -6 -6 xi = 0.00000 11.72161 23.44322 35.16484... (2048 data points) Matlab: -6.0000e+000 -1.2330e+001 -3.7384e+000 ... 7.0235e+000 7.0028e+000 6.9821e+000 SciPy: array([[ -6.00000000e+00], [ -1.56304101e+01], [ -2.04908267e+00], ..., [ 1.64475576e+05], [ 8.28360759e+04], [ -5.99999999e+00]]) Any thoughts as to how to can get results that are consistent with MatLab?

    Read the article

  • Saving a transliteration table in perl

    - by user246100
    I want to transliterate digits from 1 - 8 with 0 but not knowing the number at compile time. Since transliterations do not interpolate variables I'm doing this: @trs = (sub{die},sub{${$_[0]} =~ tr/[0,1]/[1,0]/},sub{${$_[0]} =~ tr/[0,2]/[2,0]/},sub{${$_[0]} =~ tr/[0,3]/[3,0]/},sub{${$_[0]} =~ tr/[0,4]/[4,0]/},sub{${$_[0]} =~ tr/[0,5]/[5,0]/},sub{${$_[0]} =~ tr/[0,6]/[6,0]/},sub{${$_[0]} =~ tr/[0,7]/[7,0]/},sub{${$_[0]} =~ tr/[0,8]/[8,0]/}); and then index it like: $trs[$character_to_transliterate](\$var_to_change); I would appreciate if anyone can point me to a best looking solution.

    Read the article

  • How might one implement FileTimeToSystemTime?

    - by Billy ONeal
    Hello :) I'm writing a simple wrapper around the Win32 FILETIME structure. boost::datetime has most of what I want, except I need whatever date type I end up using to interpolate with Windows APIs without issues. To that end, I've decided to write my own things for doing this -- most of the operations aren't all that complicated. I'm implementing the TimeSpan - like type at this point, but I'm unsure how I'd implement FileTimeToSystemTime. I could just use the system's built-in FileTimeToSystemTime function, except FileTimeToSystemTime cannot handle negative dates -- I need to be able to represent something like "-12 seconds". How should something like this be implemented? Billy3

    Read the article

< Previous Page | 1 2 3 4 5  | Next Page >