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  • Using Cepstrum for PDA

    - by CziX
    Hey, I am currently deleveloping a algorithm to decide wheather or not a frame is voiced or unvoiced. I am trying to use the Cepstrum to discriminate between these two situations. I use MATLAB for my implementation. I have some problems, saying something generally about the frame, but my currently implementation looks like (I'm award of the MATLAB has the function rceps, but this haven't worked for either): ceps = abs(ifft(log10(abs(fft(frame.*window')).^2+eps))); Can anybody give me a small demo, that will convert the frame to the power cepstrum, so a single lollipop at the pitch frequency. For instance use this code to generate the frequency. fs = 8000; timelength = 25e-3; freq = 500; k = 0:1/fs:timelength-(1/fs); s = 0.8*sin(2*pi*freq*k); Thanks.

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  • How to generate a lower frequency version of a signal in Matlab?

    - by estourodepilha.com
    With a sine input, I tried to modify it's frequency cutting some lower frequencies in the spectrum, shifting the main frequency towards zero. As the signal is not fftshifted I tried to do that by eliminating some samples at the begin and at the end of the fft vector: interval = 1; samplingFrequency = 44100; signalFrequency = 440; sampleDuration = 1 / samplingFrequency; timespan = 1 : sampleDuration : (1 + interval); original = sin(2 * pi * signalFrequency * timespan); fourierTransform = fft(original); frequencyCut = 10; %% Hertz frequencyCut = floor(frequencyCut * (length(pattern) / samplingFrequency) / 4); %% Samples maxFrequency = length(fourierTransform) - (2 * frequencyCut); signal = ifft(fourierTransform(frequencyCut + 1:maxFrequency), 'symmetric'); But it didn't work as expected. I also tried to remove the center part of the spectrum, but it wielded a higher frequency sine wave too. How to make it right?

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  • Plot hex tiles with different length sides?

    - by Phil
    I'm trying to create a basic grid of hex tiles. I found some code... s=h/Math.cos(30*Math.PI/180)/2; tile._x=x*s*1.5; tile._y=y*h+(x%2)*h/2; That does just that, but I think it's setup for hex's that have same length sides. However my hex has different length sides. It's width is 140 and it's height is 80. I could completely change the code to work with my side lengths, but I was wondering if there's a better way of doing it with the code above.

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  • How can Perl's XML::Simple ignore HTML embedded in XML?

    - by Miriam Raphael Roberts
    I have an XML file that I am pulling from the web and parsing. One of the items in the XML is a 'content' value that has HTML. I am using XML::Simple::XMLin to parse the file like so: $xml= eval { $data->XMLin($xmldata, forcearray => 1, suppressempty=> +'') }; When I use Data::Dumper to dump the hash, I discovered that SimpleXML is parsing the HTML into the hash tree: 'content' = { 'div' = [ { 'xmlns' = 'http://www.w3.org/1999/xhtml', 'p' = [ { 'a' = [ { 'href' = 'http://miamiherald.typepad.com/.a/6a00d83451b26169e20133ec6f4491970b-pi', 'style' = 'FLOAT: left', 'img' = [ etc..... This is not what I want. I want to just grab content inside of this entry. How do I do this?

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  • Bug in Mathematica's Integrate with PrincipalValue->True

    - by Janus
    It seems that Mathematica's handling of principal value integrals fails on some corner cases. Consider these two expressions (which should give the same result): Integrate[UnitBox[x]/(x0 - x), {x, -Infinity, Infinity}, PrincipalValue -> True, Assumptions -> {x0 > 0}] /. x0 -> 1 // Simplify Integrate[UnitBox[x]/(x0 - x) /. x0 -> 1, {x, -Infinity, Infinity}, PrincipalValue -> True] In Mathematica 7.0.0 I get I Pi+Log[3] Log[3] Has this been fixed in later versions? Does anybody have an idea for a (more or less) general workaround?

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  • Graphics glitch when drawing to a Cairo context obtained from a gtk.DrawingArea inside a gtk.Viewport.

    - by user410023
    I am trying to redraw the part of the DrawingArea that is visible in the Viewport in the expose-event handler. However, it seems that I am doing something wrong with the coordinates that are passed to the event handler because there is garbage at the edge of the Viewport when scrolling. Can anyone tell what I am doing wrong? Here is a small example: import pygtk pygtk.require("2.0") import gtk from numpy import array from math import pi class Circle(object): def init(self, position = [0., 0.], radius = 0., edge = (0., 0., 0.), fill = None): self.position = position self.radius = radius self.edge = edge self.fill = fill def draw(self, ctx): rect = array(ctx.clip_extents()) rect[2] -= rect[0] rect[3] -= rect[1] center = rect[2:4] / 2 ctx.arc(center[0], center[1], self.radius, 0., 2. * pi) if self.fill != None: ctx.set_source_rgb(*self.fill) ctx.fill_preserve() ctx.set_source_rgb(*self.edge) ctx.stroke() class Scene(object): class Proxy(object): directory = {} def init(self, target, layers = set()): self.target = target self.layers = layers Scene.Proxy.directory[target] = self def __init__(self, viewport): self.objects = {} self.layers = [set()] self.viewport = viewport self.signals = {} def draw(self, ctx): x = self.viewport.get_hadjustment().value y = self.viewport.get_vadjustment().value ctx.set_source_rgb(1., 1., 1.) ctx.paint() ctx.translate(x, y) for obj in self: obj.draw(ctx) def add(self, item, layer = 0): item = Scene.Proxy(item, layers = set((layer,))) assert(hasattr(item.target, "draw")) assert(isinstance(layer, int)) item.layers.add(layer) while not layer < len(self.layers): self.layers.append(set()) self.layers[layer].add(item) if not item in self.objects: self.objects[item] = set() self.objects[item].add(layer) def remove(self, item, layers = None): item = Scene.Proxy.directory[item] if layers == None: layers = self.objects[item] for layer in layers: layer.remove(item) item.layers.remove(layer) if len(item.layers) == 0: self.objects.remove(item) def __iter__(self): for layer in self.layers: for item in layer: yield item.target class App(object): def init(self): signals = { "canvas_exposed": self.update_canvas, "gtk_main_quit": gtk.main_quit } self.builder = gtk.Builder() self.builder.add_from_file("graphics_glitch.glade") self.window = self.builder.get_object("window") self.viewport = self.builder.get_object("viewport") self.canvas = self.builder.get_object("canvas") self.scene = Scene(self.viewport) signals.update(self.scene.signals) self.builder.connect_signals(signals) self.window.show() def update_canvas(self, widget, event): ctx = self.canvas.window.cairo_create() self.scene.draw(ctx) ctx.clip() if name == "main": app = App() scene = app.scene scene.add(Circle((0., 0.), 10.)) gtk.main() And the Glade file "graphics_glitch.glade": <?xml version="1.0"?> <interface> <requires lib="gtk+" version="2.16"/> <!-- interface-naming-policy project-wide --> <object class="GtkWindow" id="window"> <property name="width_request">200</property> <property name="height_request">200</property> <property name="visible">True</property> <signal name="destroy" handler="gtk_main_quit"/> <child> <object class="GtkScrolledWindow" id="scrolledwindow1"> <property name="visible">True</property> <property name="can_focus">True</property> <property name="hadjustment">h_adjust</property> <property name="vadjustment">v_adjust</property> <property name="hscrollbar_policy">automatic</property> <property name="vscrollbar_policy">automatic</property> <child> <object class="GtkViewport" id="viewport"> <property name="visible">True</property> <property name="resize_mode">queue</property> <child> <object class="GtkDrawingArea" id="canvas"> <property name="width_request">640</property> <property name="height_request">480</property> <property name="visible">True</property> <signal name="expose_event" handler="canvas_exposed"/> </object> </child> </object> </child> </object> </child> </object> <object class="GtkAdjustment" id="h_adjust"> <property name="lower">-1000</property> <property name="upper">1000</property> <property name="step_increment">1</property> <property name="page_increment">25</property> <property name="page_size">25</property> </object> <object class="GtkAdjustment" id="v_adjust"> <property name="lower">-1000</property> <property name="upper">1000</property> <property name="step_increment">1</property> <property name="page_increment">25</property> <property name="page_size">25</property> </object> </interface> Thanks! --Dan

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  • CodeRush Tricks of the Trade

    - by dr. evil
    I was using CodeRush quite while ago and now I'm planning to use it again. I've install the trial but I forgot all cool features except Alt + Home (drop a marker). And when you don't know some cool tricks it's really like burning money (since it's not cheap for personal use) What do you like about it? What are your best features? My best feature is marker: Alt + Home (and use escape to go back) P.S Dear Devxpress, if you think I helped you by asking this question I can accept some donations, a free license of CodeRush would be nice! Currently What I like most ps/pi etc. shortcut to create properties cc to create constructors pressing tab to navigate between the references F12 to find references in new cool window Ctrl + Shift + . for recent files Ctrl + Shift + Q for jumping to any function / class fe/fi for "for loops"

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  • SimpleXML adding html into Hash tree

    - by Miriam Raphael Roberts
    Question: I have an xml file that I am pulling from the web and parsing. One of the items in the xml is a 'content' value that has HTML. I am using SimpleXML/XMLin to parse the file like so: $xml= eval { $data-XMLin($xmldata, forcearray = 1, suppressempty= +'') }; When I use Dumper to dump the hash, I dsicovered that SimpleXML is parsing the HTML into the hash tree. 'content' => { 'div' => [ { 'xmlns' => 'http://www.w3.org/1999/xhtml', 'p' => [ { 'a' => [ { 'href' => 'http://miamiherald.typepad.com/.a/6a00d83451b26169e20133ec6f4491970b-pi', 'style' => 'FLOAT: left', 'img' => [ etc..... This is not what I want. I want to just grab content inside of this entry. How do I do this?

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  • recursive function's summation in MATLAB

    - by lucky
    B=[1 1 1 1 1 1....1] % vector of length N elements Xk= sin(2*pi/16) i need to find function alpha(l,k) which is having two variables l and k and a condition given that alpha(l,0)=alpha(l,-1)=alpha(l,-2)......=alpha(l,-(N-1))=0 i.e no matter what value of l ,alpha = 0 for past values A= input('no of iterations'); % no. of iterations user want N=input('N values of alpha:') alpha1=[]; for k=0:A-1 l=0:N-1 % need 10 separate alpha values for every k, which goes from 0 to A-1 alpha(l,k)= Xk + summation( B(j)*alpha(l,k-j)) % as summation goes from j=1 to N alpha1=[alpha1 alpha] end; could anyone please help me to solve this recursive function, i am new to matlab. alpha

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  • Can I get the method local variables through a stack trace in C#?

    - by smwikipedia
    I want to get a detailed log about my stack trace. I can get a StackFrame and then the method and then get all the parameters of that method. Just as the following code: StackTrace st = new StackTrace(); StackFrame[] sfs = st.GetFrames(); foreach (StackFrame sf in sfs) { MethodBase method = sf.GetMethod(); ParameterInfo[] pis = method.GetParameters(); foreach (ParameterInfo pi in pis) { .... } Console.WriteLine(method.Name); } But how could I get the local variables infomation within a method? Could someone shed some light on me? Many thanks.

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  • Create a bubble effect on a grid OpenGL-ES

    - by Charles Michael
    Hi there. I have created a grid with 40 x 40 vertex3D (small but useful) I can pick a single vertex out of that grid by simply calling a function with the position array[X][Y], And therefore neighbors too. How can I raise up neighbor vertex Z value so they kinda look like a bubble or sphere kind of thingy? My first tough was to use: Neighbor_vertex.Z = sin(PI/4 * 1 - ( 1/ distance_between_Neighbor_and_Pivot) ) * desired_Max_Height But all I got is something like a wave.... and I would like to have a bubble or Sphere like shape. THX dudes and dudettes

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  • slowly rotate an object towards another object

    - by numerical25
    I have an object that points in the direction of another object (i.e. it rotates to the direction that the second objects x and y coordinates are at) below is the code I use. var distx = target.x - x; var disty = target.y - y; var angle:Number = Math.atan2(disty, distx); var vx:Number = Math.cos(angle) * cspeed; var vy:Number = Math.sin(angle) * cspeed; rotation = angle * 180/Math.PI; x += vx; y += vy; as you can see. Not only does it rotate towards the target object, but it also moves towards it too. When I play the movie, the object instantly points to the targeted object and moves towards it. I would like for it to slowly turn towards the object instead of instantly turning towards it. anyone know how to do this.

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  • Why might different computers calculate different arithmetic results in VB.NET?

    - by Eyal
    I have some software written in VB.NET that performs a lot of calculations, mostly extracting jpegs to bitmaps and computing calculations on the pixels like convolutions and matrix multiplication. Different computers are giving me different results despite having identical inputs. What might be the reason? Edit: I can't provide the algorithm because it's proprietary but I can provide all the relevant operations: ULong \ ULong (Turuncating division) Bitmap.Load("filename.bmp') (Load a bitmap into memory) Bitmap.GetPixel(Integer, Integer) (Get a pixel's brightness) Double + Double Double * Double Math.Sqrt(Double) Math.PI Math.Cos(Double) ULong - ULong ULong * ULong ULong << ULong List.OrderBy(Of Double)(Func) Hmm... Is it possible that OrderBy is using a non-stable QuickSort and that QuickSort is using a random pivot? Edit: Just tested, nope. The sort is stable.

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  • Transparent Arc on HTML5 Canvas

    - by Rigil
    Here I have an arc with some transparency applied to one of the two gradients its using:` ctx.arc(mouseX,mouseY,radius,0, 2*Math.PI,false); var grd=ctx.createRadialGradient(mouseX,mouseY,0,mouseX,mouseY,brushSize); grd.addColorStop(1,"transparent"); grd.addColorStop(0.1,"#1f0000"); ctx.fillStyle=grd; ctx.fill(); Is there a way to now give the entire arc some transparency affecting only the arc and none of the rest of the canvas? Thanks

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  • Passing functions as arguements in Matlab

    - by Dave
    Hi, I'm trying to write a function that is gets two arrays and the name of another function as arguements. e.g. main.m: x=[0 0.2 0.4 0.6 0.8 1.0]; y=[0 0.2 0.4 0.6 0.8 1.0]; func2(x,y,'func2eq') func 2.m : function t =func2(x, y, z, 'func') //"unexpected matlab expression" error message here t= func(x,y,z); func2eq.m: function z= func2eq(x,y) z= x + sin(pi * x)* exp(y); Matlab tells gives me the above error message. I've never passed a function name as an arguement before. Where am I going wrong? p.s. sorry about the formatting of code above, I can't seems to get SO to show parts of the code as code.

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  • Compile-time trigonometry in C

    - by lhahne
    I currently have code that looks like while (very_long_loop) { ... y1 = getSomeValue(); ... x1 = y1*cos(PI/2); x2 = y2*cos(SOME_CONSTANT); ... outputValues(x1, x2, ...); } the obvious optimization would be to compute the cosines ahead-of-time. I could do this by filling an array with the values but I was wondering would it be possible to make the compiler compute these at compile-time?

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  • dose not name a type error in c++

    - by user985316
    #include <math.h> #include <stdlib.h> #include <stdio.h> #include <vector> #define IE 40 #define JE 40 #define KE 40 #define ia 7 #define ja 7 #define ka 7 #define NFREQS 3 using namespace std; main() float l,m,n,i,j,k,ic,jc,kc,nsteps,n_pml; float ddx,dt,T,epsz,muz,pi,eaf,npml; int ib,jb,kb; . . . . ic=IE*0.5 ; jc=JE*0.5 ; ....'ic'dose not name a type. ....'jc'dose not name a type.

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  • read angles in radian and convert them in degrees/minutes/seconds

    - by Amadou
    n=0; disp('This program performs an angle conversion'); disp('input data set to a straight line. Enter the name'); disp('of the file containing the input Lambda in radian: '); filename = input(' ','s'); [fid,msg] = fopen(filename,'rt'); if fid < 0 disp(msg); else A=textscan(fid, '%g',1); while ~feof(fid) Lambda = A(1); n = n + 1; A = textscan(fid, '%f',1); end fclose(fid); end Alpha=Lambda*180/pi; fprintf('Angle converted from radian to degree/minutes/seconds:\n'); fprintf('Alpha =%12d\n',Alpha); fprintf('No of angles =%12d\n',n);

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  • Improving the join of two wave file?

    - by kaki
    I have written a code for joining two wave files.It works fine when i am joining larger segments but as i need to join very small segments the clarity is not good. I have learned that the signal processing technique such a windowed join can be used to improve the joining of file. y[n] = w[n]s[n] Multiply value of signal at sample number n by the value of a windowing function hamming window w[n]= .54 - .46*cos(2*Pi*n)/L 0 I am not understanding how to get the value to signal at sample n and how to implement this?? the code i am using for joining is import wave m=['C:/begpython/S0001_0002.wav', 'C:/begpython/S0001_0001.wav'] i=1 a=m[i] infiles = [a, "C:/begpython/S0001_0002.wav", a] outfile = "C:/begpython/S0001_00367.wav" data= [] data1=[] for infile in infiles: w = wave.open(infile, 'rb') data1=[w.getnframes] data.append( [w.getparams(), w.readframes(w.getnframes())] ) #data1 = [ord(character) for character in data1] #print data1 #data1 = ''.join(chr(character) for character in data1) w.close() output = wave.open(outfile, 'wb') output.setparams(data[0][0]) output.writeframes(data[0][1]) output.writeframes(data[1][1]) output.writeframes(data[2][1]) output.close()

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  • Creating a new plugin for mpld3

    - by sjp14051
    Toward learning how to create a new mpld3 plugin, I took an existing example, LinkedDataPlugin (http://mpld3.github.io/examples/heart_path.html), and modified it slightly by deleting references to lines object. That is, I created the following: class DragPlugin(plugins.PluginBase): JAVASCRIPT = r""" mpld3.register_plugin("drag", DragPlugin); DragPlugin.prototype = Object.create(mpld3.Plugin.prototype); DragPlugin.prototype.constructor = DragPlugin; DragPlugin.prototype.requiredProps = ["idpts", "idpatch"]; DragPlugin.prototype.defaultProps = {} function DragPlugin(fig, props){ mpld3.Plugin.call(this, fig, props); }; DragPlugin.prototype.draw = function(){ var patchobj = mpld3.get_element(this.props.idpatch, this.fig); var ptsobj = mpld3.get_element(this.props.idpts, this.fig); var drag = d3.behavior.drag() .origin(function(d) { return {x:ptsobj.ax.x(d[0]), y:ptsobj.ax.y(d[1])}; }) .on("dragstart", dragstarted) .on("drag", dragged) .on("dragend", dragended); patchobj.path.attr("d", patchobj.datafunc(ptsobj.offsets, patchobj.pathcodes)); patchobj.data = ptsobj.offsets; ptsobj.elements() .data(ptsobj.offsets) .style("cursor", "default") .call(drag); function dragstarted(d) { d3.event.sourceEvent.stopPropagation(); d3.select(this).classed("dragging", true); } function dragged(d, i) { d[0] = ptsobj.ax.x.invert(d3.event.x); d[1] = ptsobj.ax.y.invert(d3.event.y); d3.select(this) .attr("transform", "translate(" + [d3.event.x,d3.event.y] + ")"); patchobj.path.attr("d", patchobj.datafunc(ptsobj.offsets, patchobj.pathcodes)); } function dragended(d, i) { d3.select(this).classed("dragging", false); } } mpld3.register_plugin("drag", DragPlugin); """ def __init__(self, points, patch): print "Points ID : ", utils.get_id(points) self.dict_ = {"type": "drag", "idpts": utils.get_id(points), "idpatch": utils.get_id(patch)} However, when I try to link the plugin to a figure, as in plugins.connect(fig, DragPlugin(points[0], patch)) I get an error, 'module' is not callable, pointing to this line. What does this mean and why doesn't it work? Thanks. I'm adding additional code to show that linking more than one Plugin might be problematic. But this may be entirely due to some silly mistake on my part, or there is a way around it. The following code based on LinkedViewPlugin generates three panels, in which the top and the bottom panel are supposed to be identical. Mouseover in the middle panel was expected to control the display in the top and bottom panels, but updates occur in the bottom panel only. It would be nice to be able to figure out how to reflect the changes in multiple panels. Thanks. import matplotlib import matplotlib.pyplot as plt import numpy as np import mpld3 from mpld3 import plugins, utils class LinkedView(plugins.PluginBase): """A simple plugin showing how multiple axes can be linked""" JAVASCRIPT = """ mpld3.register_plugin("linkedview", LinkedViewPlugin); LinkedViewPlugin.prototype = Object.create(mpld3.Plugin.prototype); LinkedViewPlugin.prototype.constructor = LinkedViewPlugin; LinkedViewPlugin.prototype.requiredProps = ["idpts", "idline", "data"]; LinkedViewPlugin.prototype.defaultProps = {} function LinkedViewPlugin(fig, props){ mpld3.Plugin.call(this, fig, props); }; LinkedViewPlugin.prototype.draw = function(){ var pts = mpld3.get_element(this.props.idpts); var line = mpld3.get_element(this.props.idline); var data = this.props.data; function mouseover(d, i){ line.data = data[i]; line.elements().transition() .attr("d", line.datafunc(line.data)) .style("stroke", this.style.fill); } pts.elements().on("mouseover", mouseover); }; """ def __init__(self, points, line, linedata): if isinstance(points, matplotlib.lines.Line2D): suffix = "pts" else: suffix = None self.dict_ = {"type": "linkedview", "idpts": utils.get_id(points, suffix), "idline": utils.get_id(line), "data": linedata} class LinkedView2(plugins.PluginBase): """A simple plugin showing how multiple axes can be linked""" JAVASCRIPT = """ mpld3.register_plugin("linkedview", LinkedViewPlugin2); LinkedViewPlugin2.prototype = Object.create(mpld3.Plugin.prototype); LinkedViewPlugin2.prototype.constructor = LinkedViewPlugin2; LinkedViewPlugin2.prototype.requiredProps = ["idpts", "idline", "data"]; LinkedViewPlugin2.prototype.defaultProps = {} function LinkedViewPlugin2(fig, props){ mpld3.Plugin.call(this, fig, props); }; LinkedViewPlugin2.prototype.draw = function(){ var pts = mpld3.get_element(this.props.idpts); var line = mpld3.get_element(this.props.idline); var data = this.props.data; function mouseover(d, i){ line.data = data[i]; line.elements().transition() .attr("d", line.datafunc(line.data)) .style("stroke", this.style.fill); } pts.elements().on("mouseover", mouseover); }; """ def __init__(self, points, line, linedata): if isinstance(points, matplotlib.lines.Line2D): suffix = "pts" else: suffix = None self.dict_ = {"type": "linkedview", "idpts": utils.get_id(points, suffix), "idline": utils.get_id(line), "data": linedata} fig, ax = plt.subplots(3) # scatter periods and amplitudes np.random.seed(0) P = 0.2 + np.random.random(size=20) A = np.random.random(size=20) x = np.linspace(0, 10, 100) data = np.array([[x, Ai * np.sin(x / Pi)] for (Ai, Pi) in zip(A, P)]) points = ax[1].scatter(P, A, c=P + A, s=200, alpha=0.5) ax[1].set_xlabel('Period') ax[1].set_ylabel('Amplitude') # create the line object lines = ax[0].plot(x, 0 * x, '-w', lw=3, alpha=0.5) ax[0].set_ylim(-1, 1) ax[0].set_title("Hover over points to see lines") linedata = data.transpose(0, 2, 1).tolist() plugins.connect(fig, LinkedView(points, lines[0], linedata)) # second set of lines exactly the same but in a different panel lines2 = ax[2].plot(x, 0 * x, '-w', lw=3, alpha=0.5) ax[2].set_ylim(-1, 1) ax[2].set_title("Hover over points to see lines #2") plugins.connect(fig, LinkedView2(points, lines2[0], linedata)) mpld3.show()

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  • Putting $$s in the middle of an `equation` environment: why doesn't Latex complain?

    - by Charles Stewart
    I was surprised that the Latex code from a recent question didn't throw up any errors, and even more surprised on further investigation, that Crowley's explanation seems to be true. My intuition about the \begin{equation} ... \end{equation} code is clearly off, what's really going on? Consider this, slightly adapted code: \begin{equation} 1: e^{i\pi}+1=0 $$ 2: B\"ob $$ 3: e=mc^2 \end{equation} This seems to prove that Crowley's explanation of such code, namely that "What that code says to LaTeX is begin equation, end it, begin it again, typeset definition of tangens and end the equation" is right: lines 1&3 can only be typeset in maths mode, line 2 only in text mode. Shouldn't Latex see that the \end{equation} is ending a display math that wasn't started by the \begin{equation}?

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  • LWJGL Circle program create's an oval-like shape

    - by N1ghtk1n9
    I'm trying to draw a circle in LWJGL, but when I draw I try to draw it, it makes a shape that's more like an oval rather than a circle. Also, when I change my circleVertexCount 350+, the shape like flips out. I'm really not sure how the code works that creates the vertices(I have taken Geometry and I know the basic trig ratios). I haven't really found that good of tutorials on creating circles. Here's my code: public class Circles { // Setup variables private int WIDTH = 800; private int HEIGHT = 600; private String title = "Circle"; private float fXOffset; private int vbo = 0; private int vao = 0; int circleVertexCount = 300; float[] vertexData = new float[(circleVertexCount + 1) * 4]; public Circles() { setupOpenGL(); setupQuad(); while (!Display.isCloseRequested()) { loop(); adjustVertexData(); Display.update(); Display.sync(60); } Display.destroy(); } public void setupOpenGL() { try { Display.setDisplayMode(new DisplayMode(WIDTH, HEIGHT)); Display.setTitle(title); Display.create(); } catch (LWJGLException e) { e.printStackTrace(); System.exit(-1); } glClearColor(0.0f, 0.0f, 0.0f, 0.0f); } public void setupQuad() { float r = 0.1f; float x; float y; float offSetX = 0f; float offSetY = 0f; double theta = 2.0 * Math.PI; vertexData[0] = (float) Math.sin(theta / circleVertexCount) * r + offSetX; vertexData[1] = (float) Math.cos(theta / circleVertexCount) * r + offSetY; for (int i = 2; i < 400; i += 2) { double angle = theta * i / circleVertexCount; x = (float) Math.cos(angle) * r; vertexData[i] = x + offSetX; } for (int i = 3; i < 404; i += 2) { double angle = Math.PI * 2 * i / circleVertexCount; y = (float) Math.sin(angle) * r; vertexData[i] = y + offSetY; } FloatBuffer vertexBuffer = BufferUtils.createFloatBuffer(vertexData.length); vertexBuffer.put(vertexData); vertexBuffer.flip(); vao = glGenVertexArrays(); glBindVertexArray(vao); vbo = glGenBuffers(); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER,vertexBuffer, GL_STATIC_DRAW); glVertexAttribPointer(0, 2, GL_FLOAT, false, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, 0); glBindVertexArray(0); } public void loop() { glClear(GL_COLOR_BUFFER_BIT); glBindVertexArray(vao); glEnableVertexAttribArray(0); glDrawArrays(GL_TRIANGLE_FAN, 0, vertexData.length / 2); glDisableVertexAttribArray(0); glBindVertexArray(0); } public static void main(String[] args) { new Circles(); } private void adjustVertexData() { float newData[] = new float[vertexData.length]; System.arraycopy(vertexData, 0, newData, 0, vertexData.length); if(Keyboard.isKeyDown(Keyboard.KEY_W)) { fXOffset += 0.05f; } else if(Keyboard.isKeyDown(Keyboard.KEY_S)) { fXOffset -= 0.05f; } for(int i = 0; i < vertexData.length; i += 2) { newData[i] += fXOffset; } FloatBuffer newDataBuffer = BufferUtils.createFloatBuffer(newData.length); newDataBuffer.put(newData); newDataBuffer.flip(); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferSubData(GL_ARRAY_BUFFER, 0, newDataBuffer); glBindBuffer(GL_ARRAY_BUFFER, 0); } } 300 Vertex Count(This is my main problem) 400 Vertex Count - I removed this image, it's bugged out, should be a tiny sliver cut out from the right, like a secant 500 Vertex Count Each 100, it removes more and more of the circle, and so on.

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  • Python win32api not moving mouse cursor in VirtualBox

    - by wes
    I'm trying to use this Python code: import math for i in xrange(500): x = 500 + math.sin(math.pi * i / 100) * 500 y = 500 + math.cos(i) * 100 x, y = int(x), int(y) win32api.SetCursorPos((x, y)) time.sleep(.01) taken from here to move the mouse cursor in an XP VirtualBox. The mouse icon will flicker to the appropriate graphic (when it hits the edge of a window it turns into the <- resize image, for instance), but it doesn't actually move the visible cursor. I can move the mouse around while the code is running. Same result using the ctypes example in the above link. It works fine in the Win7 host. I have Guest Additions installed, if that matters.

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  • What is wrong with this simple type definition? (Expecting one more argument to...)

    - by fluteflute
    basic.hs: areaCircle :: Floating -> Floating areaCircle r = pi * r * r Command: *Main> :l basic.hs [1 of 1] Compiling Main ( Sheet1.hs, interpreted ) Sheet1.hs:2:15: Expecting one more argument to `Floating' In the type signature for `areaCircle': areaCircle :: Floating -> Floating Failed, modules loaded: none. I see that areaCircle :: Floating a => a -> a loads as expected. Why is the above version not acceptable?

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  • C++Math evaluating incorrectly

    - by Hayden
    I thought I can make life a little easier in data statistics by making a small program which returns the results of sampling distribution of the mean (with standard error). It does this part successfully but in an attempt to return the z-score by using the formula I found here, it returns -1#IND. My interpretation of that formula is: ((1/(sqrt(2*pi)*stdev))*pow(e, (normalpow)) where double normalpow=-0.5*((mean-popmean)*(mean-popmean)/stdev) I did a little more investigating and found that (mean-popmean)*(mean-popmean) was evaluating to 0 no matter what. How can I get around this problem of normalpow evaluating to 0.

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