Skip to main content

Error Handling

 Formula errors are common. If you have a data set with hundreds of records, a divide-by-zero and an #N/A errors are bound to pop up now and then.

In the past, preventing errors required Herculean efforts. Nod your head knowingly if you’ve ever knocked out =IF(ISNA(VLOOKUP(A2,Table,2,0),"Not Found",VLOOKUP(A2,Table,2,0)). Besides being really long to type, that solution requires twice as many VLOOKUPs. First, you do a VLOOKUP to see if the VLOOKUP is going to produce an error. Then you do the same VLOOKUP again to get the non-error result.

Excel 2010 introduced the greatly improved =IFERROR(Formula,Value If Error). I know that IFERROR sounds like the old ISERROR, ISERR, and ISNA functions, but it is completely different.

This is a brilliant function: =IFERROR(VLOOKUP(A2,Table,2,0),"Not Found"). If you have 1,000 VLOOKUPs and only 5 return #N/A, then the 995 that worked require only a single VLOOKUP. Only the 5 VLOOKUPs returned #N/A that need to move on to the second argument of IFERROR.

Oddly, Excel 2013 added the IFNA() function. It is just like IFERROR but only looks for #N/A errors. One might imagine a strange situation where the value in the lookup table is found, but the resulting answer is a division by 0. If you want to preserve the divide-by-zero error for some reason, you can use IFNA() to do this.

A formula of =IFNA(VLOOKUP(),"Not Found") makes sure that you never see a #N/A error.

Of course, the person who built the lookup table should have used IFERROR to prevent the division by zero in the first place. In the figure below, the "n.m." is a former manager’s code for “not meaningful.”

The #DIV/0 error is changed to "n.m." by using =IFERROR(F9/E9,"n.m.")
Labels:

Comments

Post a Comment

Popular posts from this blog

Protect rows from getting deleted

Toggle navigation   MrExcel Home Here is an odd use for an array formula: Say that you don‘t want anyone to delete or insert any rows in one section of a worksheet. Scroll far to the right, off the screen, and build an array in those rows. Select Z1:Z9. Type  =2  and press  Ctrl+Shift+Enter . You can use any number,  =0 ,  =1 ,  =2 , and so on. If someone tries to delete a row, Excel prevents it and shows a cryptic message about arrays, shown below.
Post a Comment
Read more

Rank Function

How to Use the RANK Function If you give the RANK function a number, and a list of numbers, it will tell you the rank of that number in the list, either in ascending or descending order. For example, in the screen shot below, there is a list of 10 student test scores, in cells B2:B11. To find the rank of the the first student's score in cell B2, enter this formula in cell C2: =RANK(B2,$B$2:$B$11) Then, copy the formula from cell C2 down to cell C11, and the scores will be ranked in descending order. RANK Function Arguments There are 3 arguments for the RANK function: number : in the above example, the number to rank is in cell  B2 ref : We want to compare the number to the list of numbers in cells  $B$2:$B$11 . Use an absolute reference ($B$2:$B11), instead of a relative reference (B2:B11)so the referenced range will stay the same when you copy the formula down to the cells below order : (optional) This argument tells Excel whether to rank the list in ascending or descending o...
Post a Comment
Read more

What if Analysis

Sometimes, you want to see many different results from various combinations of inputs. Provided that you have only two input cells to change, the Data Table feature will do a sensitivity analysis. Using the loan payment example, say that you want to calculate the price for a variety of principal balances and for a variety of terms. Make sure that the formula you want to model is in the top-left corner of a range. Put various values for one variable down the left column and various values for another variable across the top. From the Data tab, select What-If Analysis, Data Table.... You have values along the top row of the input table. You want Excel to plug those values into a certain input cell. Specify that input cell for Row Input Cell. You have values along the left column. You want those plugged into another input cell. Specify that cell for the Column Input Cell. When you click OK, Excel repeats the formula in the top-left column for all combinations of the top row and left colum...
Post a Comment
Read more