Skip to main content

output formatting - Constructing a list that includes a leading zero (01,02,03 ... 55, 56, etc.)



I am constructing a list for use in file operations. Say I want to create list which contains values from 01 to 87. The kicker is that the first nine integers need to keep a value of 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11.. etc.


So if I create list=Range[87] I generate a list of integers. Whenever I'm trying to then replace values with '01', etc. they become strings. If they are integers, they revert back to the single value. Ideally, I need a list that I can feed through Do[].


Is there a quick way to create a list that uses the two digit form the whole time?


FWIW, the specific application of this that I have a list of files i.e. {1997-01-page100.jpeg, 1997-01-page101,jpeg, <<33 379>>, 1997-87-page9.jpeg, 1997-87-page10,jpeg}. I'm using the following command to generate specific lists of the sub-file using importlist=FileNames["1997-"<>ToString[x]<>"-*.jpeg"] but am being thrown off by the zero in front of the single-digit file number.



Answer



I always use IntegerString for this (I also number my files in a similar way):


In[1]:= IntegerString[#, 10, 2] & /@ Range[87]

Out[1]= {"01", "02", "03", "04", "05", "06", "07", "08", "09", "10", \
"11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", \

"22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", \
"33", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", \
"44", "45", "46", "47", "48", "49", "50", "51", "52", "53", "54", \
"55", "56", "57", "58", "59", "60", "61", "62", "63", "64", "65", \
"66", "67", "68", "69", "70", "71", "72", "73", "74", "75", "76", \
"77", "78", "79", "80", "81", "82", "83", "84", "85", "86", "87"}

I think this is the most convenient solution, as it's built-in and doesn't require any additional effort to get it working.


Comments

Post a Comment

Popular posts from this blog

functions - Get leading series expansion term?

Given a function f[x] , I would like to have a function leadingSeries that returns just the leading term in the series around x=0 . For example: leadingSeries[(1/x + 2)/(4 + 1/x^2 + x)] x and leadingSeries[(1/x + 2 + (1 - 1/x^3)/4)/(4 + x)] -(1/(16 x^3)) Is there such a function in Mathematica? Or maybe one can implement it efficiently? EDIT I finally went with the following implementation, based on Carl Woll 's answer: lds[ex_,x_]:=( (ex/.x->(x+O[x]^2))/.SeriesData[U_,Z_,L_List,Mi_,Ma_,De_]:>SeriesData[U,Z,{L[[1]]},Mi,Mi+1,De]//Quiet//Normal) The advantage is, that this one also properly works with functions whose leading term is a constant: lds[Exp[x],x] 1 Answer Update 1 Updated to eliminate SeriesData and to not return additional terms Perhaps you could use: leadingSeries[expr_, x_] := Normal[expr /. x->(x+O[x]^2) /. a_List :> Take[a, 1]] Then for your examples: leadingSeries[(1/x + 2)/(4 + 1/x^2 + x), x] leadingSeries[Exp[x], x] leadingSeries[(1/x + 2 + (1 - 1/x...
Post a Comment
Read more

How to thread a list

I have data in format data = {{a1, a2}, {b1, b2}, {c1, c2}, {d1, d2}} Tableform: I want to thread it to : tdata = {{{a1, b1}, {a2, b2}}, {{a1, c1}, {a2, c2}}, {{a1, d1}, {a2, d2}}} Tableform: And I would like to do better then pseudofunction[n_] := Transpose[{data2[[1]], data2[[n]]}]; SetAttributes[pseudofunction, Listable]; Range[2, 4] // pseudofunction Here is my benchmark data, where data3 is normal sample of real data. data3 = Drop[ExcelWorkBook[[Column1 ;; Column4]], None, 1]; data2 = {a #, b #, c #, d #} & /@ Range[1, 10^5]; data = RandomReal[{0, 1}, {10^6, 4}]; Here is my benchmark code kptnw[list_] := Transpose[{Table[First@#, {Length@# - 1}], Rest@#}, {3, 1, 2}] &@list kptnw2[list_] := Transpose[{ConstantArray[First@#, Length@# - 1], Rest@#}, {3, 1, 2}] &@list OleksandrR[list_] := Flatten[Outer[List, List@First[list], Rest[list], 1], {{2}, {1, 4}}] paradox2[list_] := Partition[Riffle[list[[1]], #], 2] & /@ Drop[list, 1] RM[list_] := FoldList[Transpose[{First@li...
Post a Comment
Read more

front end - keyboard shortcut to invoke Insert new matrix

I frequently need to type in some matrices, and the menu command Insert > Table/Matrix > New... allows matrices with lines drawn between columns and rows, which is very helpful. I would like to make a keyboard shortcut for it, but cannot find the relevant frontend token command (4209405) for it. Since the FullForm[] and InputForm[] of matrices with lines drawn between rows and columns is the same as those without lines, it's hard to do this via 3rd party system-wide text expanders (e.g. autohotkey or atext on mac). How does one assign a keyboard shortcut for the menu item Insert > Table/Matrix > New... , preferably using only mathematica? Thanks! Answer In the MenuSetup.tr (for linux located in the $InstallationDirectory/SystemFiles/FrontEnd/TextResources/X/ directory), I changed the line MenuItem["&New...", "CreateGridBoxDialog"] to read MenuItem["&New...", "CreateGridBoxDialog", MenuKey["m", Modifiers-...
Post a Comment
Read more