In Excel, I have a table with "years" column not sorted (it's a calculation result) and a "value" columns and I want to draw a chart of these values.
Scatter plot xy require ordered x numbers.
Line chart doesn't plot x values proportionally. How can I do ?
(I use MS Excel 365)
A few formulas will fix the data for you. Columns A and B contain your original data. Columns C thru F have formulas in these cells, copied down as far as needed:
C2: =RANK(A2,A$2:A$12,1)+COUNTIF(A$2:A2,A2)-1
D2: (not formulas, just values 1, 2, 3, etc.)
E2: =INDEX(A$2:A$12,MATCH($D2,$C$2:$C$12,0))
F2: =INDEX(B$2:B$12,MATCH($D2,$C$2:$C$12,0))
Just plot columns E and F in your chart.
If you have the new Dynamic Arrays, it's even easier. Columns A and B have the original data. These formulas are only entered into the indicated cells, and they fill values down automagically:
C2: =SORT(A2:A12)
D2: =SORTBY(B2:B12,A2:A12)
A solution is to use the line chart specifying x-axis as a "date axis".
Double click the x-axis, on the side bar choose axis options icon 
then select "Date axis" 
.
Drawback of this method: the fractional parts of the X values are not displayed.
Specifying the number format of X-axis labels with "decimal places: 0" gives me an acceptable result.
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