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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to plot ROC curve in Python?
ROC − Receiver operating characteristics (ROC) curve.Using metrics.plot_roc_curve(clf, X_test, y_test) method, we can draw the ROC curve.StepsGenerate a random n-class classification problem. This initially creates clusters of points normally distributed (std=1) about vertices of an ``n_informative``-dimensional hypercube with sides of length ``2*class_sep`` and assigns an equal number of clusters to each class.It introduces interdependence between these features and adds various types of further noise to the data. Use the make_classification() method.Split arrays or matrices into random trains, using train_test_split() method.Fit the SVM model according to the given training data, using fit() method.Plot Receiver operating characteristic (ROC) curve, using plot_roc_curve() method.To ...
Read MoreDefining the midpoint of a colormap in Matplotlib
Using plt.subplots(1, 1) method, we can create fig and axis. We can use fig.colorbar to make the color bar at the midpoint of the figure.StepsUsing mgrid() method, `nd_grid` instance which returns an open multi-dimensional "meshgrid".Create Z1, Z2 and Z data.Create fig and ax variables using subplots method, where default nrows and ncols are 1, using subplots() method.Create a colorbar for a ScalarMappable instance, *mappable*, using colorbar() method.Using plt.show(), we can show the figure.Exampleimport numpy as np import matplotlib.pyplot as plt import matplotlib.colors as colors N = 100 X, Y = np.mgrid[-3:3:complex(0, N), -2:2:complex(0, N)] Z1 = np.exp(-(X)**2 - ...
Read MorePrint dates of today, yesterday and tomorrow using Numpy
In this program, we will print today's, yesterday's and tomorrow's dates using the numpy library.AlgorithmStep 1: Import the numpy library. Step 2: find today's date using the datetime64() function. Step 3: find yesterday's date by subtracting the output of timedelta64() function from the output of datetime64() function. Step 4: Find yesterday's date by adding the output of timedelta64() function from the output of datetime64() function.Example Codeimport numpy as np todays_date = np.datetime64('today', 'D') print("Today's Date: ", todays_date) yesterdays_date = np.datetime64('today', 'D') - np.timedelta64(1, 'D') print("Yesterday's Date: ", yesterdays_date) tomorrows_date = np.datetime64('today', 'D') + np.timedelta64(1, 'D') print("Tomorrow's Date: ...
Read MoreHow to draw different shapes using the Python Turtle library?
In this program, we will draw different shapes using the Turtle library in Python. Turtle is a python feature like a drawing board, which lets you command a turtle to draw all over it. The different shapes that we are going to draw are square, rectangle, circle and a hexagon.AlgorithmStep 1: Take lengths of side for different shapes as input.Step 2: Use different turtle methods like forward() and left() for drawing different shapes.Example Codeimport turtle t = turtle.Turtle() #SQUARE side = int(input("Length of side: ")) for i in range(4): t.forward(side) t.left(90) #RECTANGLE side_a = int(input("Length of ...
Read MoreScatter plot and Color mapping in Python
We can create a scatter plot using the scatter() method and we can set the color for every data point.StepsCreate random values (for x and y) in a given shape, using np.random.rand() method.Create a scatter plot of *y* vs. *x* with varying marker size and/or color, using the scatter method where color range would be in the range of (0, 1000).Show the figure using plt.show().Exampleimport matplotlib.pyplot as plt import numpy as np x = np.random.rand(1000) y = np.random.rand(1000) plt.scatter(x, y, c=[i for i in range(1000)]) plt.show()Output
Read MoreChange figure window title in pylab(Python)
Using pylab.gcf(), we can create a fig variable and can set the fig.canvas.set_window_title('Setting up window title.') window title.StepsUsing gcf() method, get the current figure. If no current figure exists, a new one is created using `~.pyplot.figure()`.Set the title text of the window containing the figure, using set_window_title() method.. Note that this has no effect if there is no window (e.g., a PS backend).ExamplePlease use Ipython and follow the steps given below -In [1]: from matplotlib import pylab In [2]: fig = pylab.gcf() In [3]: fig.canvas.set_window_title('Setting up window title.')Output
Read MorePython program to compare two Pandas series
In this program, we will declare two Pandas series and compare their elements. Before we solve the problem, we need to import the Pandas library into our local IDE. This can be done by installing Pandas on our local machine. The command for installing Pandas is −pip install pandasInputSeries1 = [2,4,6,8,10]Series2 = [1,3,5,7,9]AlgorithmStep 1: Define two Pandas series using the Series() function of Pandas library.Step 2: Compare the series using greater than, less than, and equal-to operators.Example Codeimport pandas as pd series1 = pd.Series([2,4,6,8,10]) series2 = pd.Series([1,3,5,7,9]) print("Greater Than: ",series1>series2) print("Less Than: ",series1
Read MoreExplain scope rules related to the functions in C language
Scope rules are related to the following factors −Accessibility of a variables.Period of existence of a variable.Boundary of usage of variables.Scope rules related to functions are as followsFunction which is a self-contained block that performs a particular task.Variables that are declared within the function body are called local variables.These variables only exist inside the specific function that creates them. They are unknown to other functions and to the main functions too.The existence of local variables ends when the function completes its specific task and returns to the calling point.Example 1Following is the C program for scope rules related to functions ...
Read MoreWhat are the predefined functions in C language?
Functions are broadly classified into two types, which are as follows −Predefined functionsUser defined functionsPredefined (or) library functionsThese functions are already defined in the system libraries.Programmer will reuse the already present code in the system libraries to write error free code.But to use the library functions, user must be aware of syntax of the function.Example −sqrt() function is available in math.h library and its usage is −y= sqrt (x) x number must be positive eg: y = sqrt (25) then ‘y’ = 5printf ( ) present in stdio.h library.clrscr ( ) present in conio.h library.ExampleGiven below is the C program ...
Read MoreFind number of subarrays with even sum in C++
In this problem, we are given an array arr[] consisting of N elements. Our task is to find the subarray with even sum.Let’s take an example to understand the problem, Inputarr[] = {2, 1, 3, 4, 2, 5}Output28ExplanationThe subarrays are −{2}, {4}, {2}, {2, 4}, {2, 2}, {1, 3}, {1, 5}, {3, 5}, {4, 2}, {2, 1, 3}, {2, 1, 5}, {2, 3, 5}, {2, 4, 2}, {1, 3, 4}, {1, 3, 2}, {1, 4, 5}, {1, 2, 5}, {3, 4, 5}, {3, 2, 5}, {2, 1, 3, 4}, {2, 1, 3, 2}, {2, 3, 4, 5}, {2, 3, 2, ...
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