Export solution in form assigning variable with subscript

Question

I can find solutions of linear equations like below:

sol = Flatten[  Solve[{2 Subscript[C, 1] + 2 Subscript[C, 2] == -1, 
     2 Subscript[C, 1] + 3 Subscript[C, 2] == 1}]] 
Export["sol.csv", sol, "CSV"]
sol = Import["sol.csv", "CSV"]

How can i export and import solution in Mathematica with appearing function subscript in list.(when i import solution function of subscript appear in my solution).

Answer 1

CSV (Comma-separated values) uses comma as delimiter and, hence, interpreting the comma in Subscript[C, 1] as a field separator, exports Subscript[C, 1] -> -5/2 as {"Subscript[C", " 1] -> -5/2"}

sol = Flatten[Solve[{2 Subscript[C, 1] + 2 Subscript[C, 2] == -1, 
    2 Subscript[C, 1] + 3 Subscript[C, 2] == 1}]]
Export["sol.csv", sol, "CSV"];
imported = Import["sol.csv", "CSV"]

{{"Subscript[C", " 1] -> -5/2"}, {"Subscript[C", " 2] -> 2"}}

this can be seen in the file sol.csv

You can use import it as TSV (Tab-separated values) instead to avoid this issue:

imported2 = Import["sol.csv", "TSV"]

{{"Subscript[C, 1] -> -5/2"}, {"Subscript[C, 2] -> 2"}}

ToExpression@imported2

Answer 2

Using

sol // ToString // ToExpression // TableForm // TraditionalForm

will give you

$C_1 \rightarrow -\frac{5}{2}$

$C_2 \rightarrow 2$.

ToString converts it to a string. ToExpression is the most important one, converting it to a mathematical expression. TableForm and TraditionalForm will make it pretty. I think you are exporting as .csv and that's why the imported format is not usable. Instead, you can use .dat or .txt.