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Articles on Trending Technologies
Technical articles with clear explanations and examples
Manually add legend Items Python Matplotlib
Using plt.legend() method, we can create a legend, and passing frameon would help to keep the border over there.StepsSet the X-axis label using plt.xlabel() method.Set the Y-axis label using plt.ylabel() method.Draw lines using plot() method.Location and legend drawn flags can help to find a location and make the flag True for the border.Set the legend with “blue” and “orange” elements.To show the figure use plt.show() method.Exampleimport matplotlib.pyplot as plt plt.ylabel("Y-axis ") plt.xlabel("X-axis ") plt.plot([9, 5], [2, 5], [4, 7, 8]) location = 0 # For the best location legend_drawn_flag = True plt.legend(["blue", "orange"], loc=0, frameon=legend_drawn_flag) plt.show()Output
Read MoreShow only certain items in legend Python Matplotlib
Using plt.legend(), we can add or show certain items just by putting the values in the list.StepsSet the X-axis label using plt.xlabel() method.Set the Y-axis label using plt.ylabel() method.Plot the lines using the lists that are passed in the plot() method argument.Location and legend_drawn flags can help to find a location and make the flag True for border.Set the legend with “blue” and “orange” elements.To show the figure use plt.show() method.Exampleimport matplotlib.pyplot as plt plt.ylabel("Y-axis ") plt.xlabel("X-axis ") plt.plot([9, 5], [2, 5], [4, 7, 8]) location = 0 # For the best location legend_drawn_flag = True plt.legend(["blue", ...
Read MoreBlurring an image using the OpenCV function blur()
In this program, we will blur an image using the opencv function blur().AlgorithmStep 1: Import OpenCV. Step 2: Import the image. Step 3: Set the kernel size. Step 4: Call the blur() function and pass the image and kernel size as parameters. Step 5: Display the results.Original ImageExample Codeimport cv2 image = cv2.imread("testimage.jpg") kernel_size = (7,7) image = cv2.blur(image, kernel_size) cv2.imshow("blur", image)OutputBlurred ImageExplanationThe kernel size is used to blur only a small part of an image. The kernel moves across the entire image and blurs the pixels it covers.
Read MoreHow to test for significant relationship between two categorical columns of an R data frame?
To test for the significance of proportion between two categorical columns of an R data frame, we first need to find the contingency table using those columns and then apply the chi square test for independence using chisq.test. For example, if we have a data frame called df that contains two categorical columns say C1 and C2 then the test for significant relationship can be done by using the command chisq.test(table(df$C1,df$C2))Example Live Demox1
Read MoreWhat does .shape[] do in “for i in range(Y.shape[0])” using Matplotlib?
The shape property is usually used to get the current shape of an array, but it may also be used to reshape the array in-place by assigning a tuple of array dimensions to it.StepsGet an array Y using np.array method.Y.shape would return a tuple (4, ).Y.shape[0] method would return 4, i.e., the first element of the tuple.Exampleimport numpy as np Y = np.array([1, 2, 3, 4]) print("Output of .show method would be: ", Y.shape, " for ", Y) print("Output of .show[0] method would be: ", Y.shape[0], " for ", Y) print("Output for i in range(Y.shape[0]): ", end=" ") for ...
Read MoreHow to replace a particular value in R data frame with a new value?
To replace a particular value in R data frame with a new value, we can use ifelse function where the new value will be placed after the condition and if the column values do not match the condition then the same column will be placed. For example, if we have a data frame called df that contains a column x having 20 values and some of them are 5 and if we want to replace 5 with 2 then we can use the command df$x
Read MoreHow to create boxplot in base R with higher width of the box lines?
To create boxplot in base R with higher width of the box lines, we can use the boxlwd argument inside boxplot function. For example, if we have a vector called x then we can create the boxplot with higher width of the box lines using the command −boxplot(x,boxlwd=5)Example Live Demox
Read MoreHow to find the fractional power of a negative number in R?
To find the fractional power of a negative number, we can find the power separately for the numerator and denominator where denominator will have the numerator 1. For example, if we have a vector called x that contains a single value -10 then the fractional power 15/7 of x can be found by using the command ((x)^15)^(1/7)Example Live Demox1
Read MoreHow to find the number of levels in R for a factor column?
To find the number of levels in R for a factor column, we can use length function along with unique function. For example, if we have a data frame called df that contains a factor column X then we can find the number of levels in the factor column using the command −length(unique(df$X))ExampleConsider the below data frame − Live Demox1
Read MoreHow to replace space between two words with underscore in an R data frame column?
To replace space between two words with underscore in an R data frame column, we can use gsub function. For example, if we have a data frame called df that contains character column x having two words having a single space between them then we can replace that space using the command df$x
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