5 replaced http://mathematica.stackexchange.com/ with https://mathematica.stackexchange.com/ edited Apr 13 '17 at 12:55 I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-datasetHow can I add a column into a existing Dataset? The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #"PS_I" * 3]&]  I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #"PS_I" * 3]&]  I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: How can I add a column into a existing Dataset? The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #"PS_I" * 3]&]  Post Closed as "off-topic" by WReach, MarcoB, Feyre, happy fish, Sascha occurred Nov 23 '16 at 10:15 4 added 2 characters in body edited Nov 21 '16 at 20:34 triplebig 19777 bronze badges I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #PS_I#"PS_I" * 3]&]  I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #"PS_I" * 3]&]  3 added 4 characters in body edited Nov 21 '16 at 20:31 triplebig 19777 bronze badges I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. I have a dataset which has a column called "PS_I". I cannot change this because I imported the column from an existing csv. I would like to add another column. Such as: data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  But that doesn't work due to underscore being a predefined character. How do I get around this? EDIT: Here's an example. This is one column with such an index: data = Dataset[ {<|"PS_I" -> 1|>, <|"PS_I" -> 2|>, <|"PS_I" -> 3|>, <|"PS_I" -> 4|>, <|"PS_I" -> 5|>, <|"PS_I" -> 6|>, <|"PS_I" -> 7|>}]  And I want to create a new column with some operation on the values of the PS_I column. Kind of what this answer suggested: http://mathematica.stackexchange.com/questions/51472/how-can-i-add-a-column-into-a-existing-dataset The underscore does not allow for these type of operations, and I would like to know how to deal with this problem. EDIT2: Here's how to reproduce the problem, now with input from JasonB: 1) Create a csv with these contents: http://pastebin.com/eYUaW2bV 2) Run data = SemanticImport["/example.csv"];  3) Try to append with data = data[All, Append[#,"newPSI" -> #PS_I * 3]&]  2 added 611 characters in body edited Nov 21 '16 at 20:20 triplebig 19777 bronze badges 1 asked Nov 21 '16 at 19:55 triplebig 19777 bronze badges