indexing

问题 Simple questions, but I can't find an answer. I have a vector a<-c(5,6,7) how can I get back the indices for all elements in my vector? I need back 1 #"a" 2 #"b" 3 #"c" or c(1,2,3) If I run seq_along(a), it gives me back (1,1,1) not (1,2,3) : for (i in seq_along(a)) { print(seq_along(a[[i]])) } [1] 1 [1] 1 [1] 1 The reason for this is that I need to create a unique name for each of my plots. I have about 100 plots illustrating 100 locations. Locations'names are too long and contain special

问题 Simple questions, but I can't find an answer. I have a vector a<-c(5,6,7) how can I get back the indices for all elements in my vector? I need back 1 #"a" 2 #"b" 3 #"c" or c(1,2,3) If I run seq_along(a), it gives me back (1,1,1) not (1,2,3) : for (i in seq_along(a)) { print(seq_along(a[[i]])) } [1] 1 [1] 1 [1] 1 The reason for this is that I need to create a unique name for each of my plots. I have about 100 plots illustrating 100 locations. Locations'names are too long and contain special

问题 I have code to append ^0 to all the constants in my code so that if you had the string "3x^2+14+2" it would become "3x^2+14^0+2^0" however I am getting a IndexError and I have no idea what I am doing wrong. This is my code: def cleanEquation(equation): equation = ''.join(equation.split()) for i in range(len(equation)): if equation[i].isdigit(): if equation[i-1] != "^": if i == len(equation)-1: equation = equation[:i+1] + '^0' if equation[i+1] == "+" or equation[i+1] == "-": equation =

问题 I have code to append ^0 to all the constants in my code so that if you had the string "3x^2+14+2" it would become "3x^2+14^0+2^0" however I am getting a IndexError and I have no idea what I am doing wrong. This is my code: def cleanEquation(equation): equation = ''.join(equation.split()) for i in range(len(equation)): if equation[i].isdigit(): if equation[i-1] != "^": if i == len(equation)-1: equation = equation[:i+1] + '^0' if equation[i+1] == "+" or equation[i+1] == "-": equation =

问题 So for example we have field 1 up to 10. I want to index all the field in Azure Search, so you can filter, search on those filters. My Question is, is there a way to just exclude the fields that are NULL from a specific ID, so not store them in Azure search? See example underneath. The data itself is initially stored in Azure Cosmos Database. In Azure Cosmos DB it would like this: Id 1 field 1: a field 2: b field 5: c field 6: d field 8: e Id 2 field 3: a field 2: b field 5: c field 9: d

问题 Using openpyxl I am creating python script that will loop through the rows of data and find rows in which some of the column are empty - these will be deleted. The range of rows is 3 to 1800. I am not excatly sure how to delete these row - please see code I have come up with so far. What I was trying to achieve is to iterate through the rows and check if columns 4, 7 values are set to None. If True I wanted to return row number into suitable collection (need advise which one would be best for

问题 Using openpyxl I am creating python script that will loop through the rows of data and find rows in which some of the column are empty - these will be deleted. The range of rows is 3 to 1800. I am not excatly sure how to delete these row - please see code I have come up with so far. What I was trying to achieve is to iterate through the rows and check if columns 4, 7 values are set to None. If True I wanted to return row number into suitable collection (need advise which one would be best for

问题 I have a dataframe, I want to change only those values of a column where another column fulfills a certain condition. I'm trying to do this with iloc at the moment and it either does not work or I'm getting that annoying warning: A value is trying to be set on a copy of a slice from a DataFrame Example: import pandas as pd DF = pd.DataFrame({'A':[1,1,2,1,2,2,1,2,1],'B':['a','a','b','c','x','t','i','x','b']}) Doing one of those DF['B'].iloc[:][DF['A'] == 1] = 'X' DF.iloc[:]['B'][DF['A'] == 1]

问题 I have a dataframe, I want to change only those values of a column where another column fulfills a certain condition. I'm trying to do this with iloc at the moment and it either does not work or I'm getting that annoying warning: A value is trying to be set on a copy of a slice from a DataFrame Example: import pandas as pd DF = pd.DataFrame({'A':[1,1,2,1,2,2,1,2,1],'B':['a','a','b','c','x','t','i','x','b']}) Doing one of those DF['B'].iloc[:][DF['A'] == 1] = 'X' DF.iloc[:]['B'][DF['A'] == 1]

问题 How can I convert the index of 1D array into 2D array? I know how to convert a 2D array into 1D (i*the size of row+j) . I want the opposite of that. 回答1: What you need to know is: How many columns should the 2D array have: Lets say you have an array of 20 columns and 10 rows (array[20,10]): int index = 47; int numberOfColumns = 20; int column = index % numberOfColumns; int row = index / numberOfColumns; // column == 7 // row == 2 回答2: You can just do the opposite. if n is the length of the