Posts (page 70)
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4 min readTo cancel a PostgreSQL transaction and do nothing, you can simply issue a ROLLBACK command without any further instructions. This will effectively cancel the current transaction and revert any changes made, but no additional actions will be taken. This approach is useful when you want to abort a transaction without triggering any specific actions or commands to be executed.
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3 min readTo modify the size of a matplotlib bar graph, you can adjust the width of the bars by using the width parameter in the bar function. Simply set the width parameter to a value that suits your design preferences. Additionally, you can also change the overall size of the graph by adjusting the figure size using the figsize parameter when creating the plot. This will allow you to customize the dimensions of your bar graph according to your specific requirements.
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5 min readManaging multiple monitors with PowerShell involves using the DisplaySwitch command to control the display settings. This command can be used to switch between different display modes, such as extending the display across multiple monitors or duplicating the screen on multiple monitors. You can also use PowerShell to control the resolution, orientation, and other display settings for each monitor individually.
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3 min readTo find and apply a text search configuration in PostgreSQL, you need to first locate the configuration file called "postgresql.conf" within your PostgreSQL installation directory. Once you have found the file, you can open it in a text editor and search for the parameter "default_text_search_config". You can then specify the text search configuration you want to use by setting the value of this parameter to the desired configuration name.
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4 min readTo get pixel RGB values using matplotlib, you can first read an image using the imread function of matplotlib.pyplot. This will return a numpy array representing the image data. Next, you can use array indexing to access the RGB values of a specific pixel by specifying its row and column coordinates. For example, to get the RGB values of a pixel at position (x, y), you can use image_array[y, x]. This will return a 1D array containing the RGB values in the order [R, G, B].
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6 min readTo run PowerShell from C# as an administrator, you can use the Process class from the System.Diagnostics namespace. You will need to create a new ProcessStartInfo object and set the FileName property to "PowerShell.exe" and the Verb property to "runas" to run PowerShell as an administrator.You can then use the Start() method of the Process class to start the PowerShell process with the specified start info.
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5 min readTo fix the PostgreSQL error fatal: password authentication failed for user <user>, you can try the following steps:Double-check the username and password you are using to connect to the PostgreSQL database. Make sure they are correct.Ensure that the user has the necessary privileges to access the database. You can do this by checking the user's roles and permissions.Verify that the PostgreSQL server is running and is configured to accept password authentication.
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4 min readTo overlay two 2D histograms in Matplotlib, you can use the imshow function provided by Matplotlib. First, plot the first histogram using imshow and specify the transparency level using the alpha parameter. Then, plot the second histogram on top of the first one using the same imshow function with a different transparency level. This will allow you to see both histograms overlaid on the same plot.
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4 min readTo wait and kill a timeout process in PowerShell, you can use the Start-Sleep cmdlet to pause the script for a specific amount of time. You can then use the Stop-Process cmdlet to forcefully terminate the process if it exceeds the timeout duration. This can be achieved by checking the process's running time and comparing it to the timeout value. If the process exceeds the timeout, you can use the Stop-Process cmdlet to kill the process.
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8 min readTo speed up an animation created using matplotlib, you can use the FuncAnimation class instead of the traditional animation. This class only updates the parts of the plot that have changed, leading to faster rendering times. You can also limit the number of frames in the animation or reduce the complexity of your plots to increase speed.Additionally, you can consider using Plotly or other libraries that may offer better performance for animations.
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3 min readTo remap array values of a column in PostgreSQL, you can use the ARRAY function along with a CASE statement to update the values. First, you need to specify the column you want to remap the values of in your UPDATE statement. Then, you can use the ARRAY function to create a new array with the remapped values based on the conditions you set in the CASE statement.
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2 min readIn PowerShell, you can use the Get-Variable cmdlet to get the variable names that are currently defined in the session. Simply run Get-Variable without any additional parameters to list all the variables along with their values. Additionally, you can use the Get-Member cmdlet to retrieve more information about the variables, such as their data type and scope. This can be helpful for debugging or when you need to access a specific variable by its name during script execution.