I have a chart, and several series contain data that comes from elsewhere
using a VLOOKUP. However, when the VLOOKUP finds a blank, it returns a zero.
I want the chart to interpolate the data, but Excel charts can only
interpolate blanks, not zeroes. I've used ISBLANK with the VLOOKUP to return
what appears to be a blank, but the chart still sees it as a zero, and thus
will not interpolate. I'd like to know if there's a way to set the value of
a cell to NULL, because "" doesn't work...

You have a couple of options for a workaround: one is to nest the
VLOOKUP into an IF formula, so the logic flow would be: IF(vlookup
value = "","",normal vlookup)

Another way to do it is to nest a MATCH function inside an INDEX
function, best shown by example: suppose values in A1:A4 are
penny
nickel
dime
quarter

....and suppose values in B1:B4 are
..01
..05
..1
..25

Copy the A1:A4 values into D1:D4 (to show that the values can appear in
a different cell, must be spelled exactly, etc). Then in cell E1,
enter this formula:
=INDEX($A$1:$B$4,MATCH(D1,$A$1:$A$4,0),2)

The English translation is: find an exact match of D1 in the range
A1:A4 (which becomes a row reference for the INDEX function); in the
range A1:B4 go to the row specified by the MATCH function and the
column number supplied (i.e., 2).

I appreciate your suggestion, but I've already nested the VLOOKUP in an IF
statement, similar to the way you've suggested. Mine follows this pattern:
IF(ISBLANK(VLOOKUP),"",VLOOKUP) I get a result that appears as a blank, but
still carries a value of zero. in your example, if you substitute a blank
for the value of a nickel instead of .05, then chart the results column (with
interpolation for blank cells), you'll see my dilemma. It won't interpolate,
because it has a zero value. The INDEX MATCH combination provides the same
result as a VLOOKUP.

"Dave O" wrote:

You have a couple of options for a workaround: one is to nest the
VLOOKUP into an IF formula, so the logic flow would be: IF(vlookup
value = "","",normal vlookup)

Another way to do it is to nest a MATCH function inside an INDEX
function, best shown by example: suppose values in A1:A4 are
penny
nickel
dime
quarter

....and suppose values in B1:B4 are
..01
..05
..1
..25

Copy the A1:A4 values into D1:D4 (to show that the values can appear in
a different cell, must be spelled exactly, etc). Then in cell E1,
enter this formula:
=INDEX($A$1:$B$4,MATCH(D1,$A$1:$A$4,0),2)

The English translation is: find an exact match of D1 in the range
A1:A4 (which becomes a row reference for the INDEX function); in the
range A1:B4 go to the row specified by the MATCH function and the
column number supplied (i.e., 2).

The #N/A error is very friendly to making graphs show null.
So, simply revise your formulas to replace the null [ "" ] with "#N/A" (no
quotes).
--

HTH,

RD
==============================================
Please keep all correspondence within the Group, so all may benefit!
==============================================

"flummoxed" wrote in message
...
I appreciate your suggestion, but I've already nested the VLOOKUP in an IF
statement, similar to the way you've suggested. Mine follows this pattern:
IF(ISBLANK(VLOOKUP),"",VLOOKUP) I get a result that appears as a blank, but
still carries a value of zero. in your example, if you substitute a blank
for the value of a nickel instead of .05, then chart the results column
(with
interpolation for blank cells), you'll see my dilemma. It won't
interpolate,
because it has a zero value. The INDEX MATCH combination provides the same
result as a VLOOKUP.

"Dave O" wrote:

You have a couple of options for a workaround: one is to nest the
VLOOKUP into an IF formula, so the logic flow would be: IF(vlookup
value = "","",normal vlookup)

Another way to do it is to nest a MATCH function inside an INDEX
function, best shown by example: suppose values in A1:A4 are
penny
nickel
dime
quarter

....and suppose values in B1:B4 are
..01
..05
..1
..25

Copy the A1:A4 values into D1:D4 (to show that the values can appear in
a different cell, must be spelled exactly, etc). Then in cell E1,
enter this formula:
=INDEX($A$1:$B$4,MATCH(D1,$A$1:$A$4,0),2)

The English translation is: find an exact match of D1 in the range
A1:A4 (which becomes a row reference for the INDEX function); in the
range A1:B4 go to the row specified by the MATCH function and the
column number supplied (i.e., 2).

Thanks! That worked like a charm -- Excel sometimes works in mysterious
ways, doesn't it? Sorry if I didn't keep a response within the group, but
this is my initial forray into this medium.

"RagDyer" wrote:

The #N/A error is very friendly to making graphs show null.
So, simply revise your formulas to replace the null [ "" ] with "#N/A" (no
quotes).
--

HTH,

RD
==============================================
Please keep all correspondence within the Group, so all may benefit!
==============================================

"flummoxed" wrote in message
...
I appreciate your suggestion, but I've already nested the VLOOKUP in an IF
statement, similar to the way you've suggested. Mine follows this pattern:
IF(ISBLANK(VLOOKUP),"",VLOOKUP) I get a result that appears as a blank, but
still carries a value of zero. in your example, if you substitute a blank
for the value of a nickel instead of .05, then chart the results column
(with
interpolation for blank cells), you'll see my dilemma. It won't
interpolate,
because it has a zero value. The INDEX MATCH combination provides the same
result as a VLOOKUP.

"Dave O" wrote:

You have a couple of options for a workaround: one is to nest the
VLOOKUP into an IF formula, so the logic flow would be: IF(vlookup
value = "","",normal vlookup)

Another way to do it is to nest a MATCH function inside an INDEX
function, best shown by example: suppose values in A1:A4 are
penny
nickel
dime
quarter

....and suppose values in B1:B4 are
..01
..05
..1
..25

Copy the A1:A4 values into D1:D4 (to show that the values can appear in
a different cell, must be spelled exactly, etc). Then in cell E1,
enter this formula:
=INDEX($A$1:$B$4,MATCH(D1,$A$1:$A$4,0),2)

The English translation is: find an exact match of D1 in the range
A1:A4 (which becomes a row reference for the INDEX function); in the
range A1:B4 go to the row specified by the MATCH function and the
column number supplied (i.e., 2).

You DID keep your response within the news group,

AND, thanks for the feed-back.

--

Regards,

RD
--------------------------------------------------------------------
Please keep all correspondence within the Group, so all may benefit !
--------------------------------------------------------------------

"flummoxed" wrote in message
...
Thanks! That worked like a charm -- Excel sometimes works in mysterious
ways, doesn't it? Sorry if I didn't keep a response within the group, but
this is my initial forray into this medium.

"RagDyer" wrote:

The #N/A error is very friendly to making graphs show null.
So, simply revise your formulas to replace the null [ "" ] with "#N/A" (no
quotes).
--

HTH,

RD
==============================================
Please keep all correspondence within the Group, so all may benefit!
==============================================

"flummoxed" wrote in message
...
I appreciate your suggestion, but I've already nested the VLOOKUP in an IF
statement, similar to the way you've suggested. Mine follows this
pattern:
IF(ISBLANK(VLOOKUP),"",VLOOKUP) I get a result that appears as a blank,
but
still carries a value of zero. in your example, if you substitute a blank
for the value of a nickel instead of .05, then chart the results column
(with
interpolation for blank cells), you'll see my dilemma. It won't
interpolate,
because it has a zero value. The INDEX MATCH combination provides the
same
result as a VLOOKUP.

"Dave O" wrote:

You have a couple of options for a workaround: one is to nest the
VLOOKUP into an IF formula, so the logic flow would be: IF(vlookup
value = "","",normal vlookup)

Another way to do it is to nest a MATCH function inside an INDEX
function, best shown by example: suppose values in A1:A4 are
penny
nickel
dime
quarter

....and suppose values in B1:B4 are
..01
..05
..1
..25

Copy the A1:A4 values into D1:D4 (to show that the values can appear in
a different cell, must be spelled exactly, etc). Then in cell E1,
enter this formula:
=INDEX($A$1:$B$4,MATCH(D1,$A$1:$A$4,0),2)

The English translation is: find an exact match of D1 in the range
A1:A4 (which becomes a row reference for the INDEX function); in the
range A1:B4 go to the row specified by the MATCH function and the
column number supplied (i.e., 2).

Insert an additional column before the column where you have your
VLOOKUP formula. Suppose that column Y is the column housing those
retrieval formula:

In X2 enter & copy down:

=IF(Y2=0,#N/A,Y2)

Exclude column Y from charts.

flummoxed wrote:
I have a chart, and several series contain data that comes from elsewhere
using a VLOOKUP. However, when the VLOOKUP finds a blank, it returns a zero.
I want the chart to interpolate the data, but Excel charts can only
interpolate blanks, not zeroes. I've used ISBLANK with the VLOOKUP to return
what appears to be a blank, but the chart still sees it as a zero, and thus
will not interpolate. I'd like to know if there's a way to set the value of
a cell to NULL, because "" doesn't work...