Please add an INTERPOLATE function. For vector or array data.

You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
from there.
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Dan Gauthier" <Dan [email protected]> wrote in message
news:[email protected]...
> Please add this function which may be used either for a vector set of data
> or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow
> this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions

Bernard Liengme wrote...
>You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
>from there.
....

LINEST would be gross overkill. Besides, FORECAST and TREND would be
far easier than any of these. The problem is that using it to
interpolate in a table (TBL) for a value (v) involves expressions like

TREND(OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),YvalCol-1,2,1),
OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),XvalCol-1,2,1),v)

You may like these, but they are a bit long. When they're general like
this, they eat 3 levels of nested function calls. A simpler approach
would be handy, but I suspect we won't see it in Excel until a few
months after Hell organizes an Ice Hockey league.

Tushar Mehta wrote...
>As nice as it would be for MS to meet every need for every function
>from every customer, XL is flexible enough to allow one to add new
>capabilities.

The logical implications of this argument are that because Excel is
extensible in terms of functions, Microsoft need never add another.

As for meeting needs, when was the last time anyone who uses Excel
regularly needed any of the 3 Bessel functions? And for those who
do need Bessel functions, it would have been nice if Microsoft had
allowed for fractional parameters.

Linear interpolation is a commonly needed bit of functionality. Not,
it'd seem, as frequently requested as summing cells by color or font
attributes, but much more common than finding solutions to
cylindrical harmonics.

It'd be good for Microsoft to add some built-in functions to Excel.
But, if you're going to be an absolutist about this (denying the need
or usefullness of any more functions), perhaps we could discuss new
capabilities that would make Excel *MORE* *CONSISTENT*.

Top of my list would be rewriting the formula parser (which probably
hasn't been touched since Excel 4) to accept nested function calls
more than 7 levels deep. As I've pointed out several times, Excel has
no trouble calculating such formulas, but it won't allow them to be
created or edited. How can they be? They can be created by other,
non-Microsoft spreadsheets, saved in .XLS format (so the file format
in addition to the recalc engine isn't the problem here), and opened
in Excel. Would that be a useful new feature?

>For a few options for piecewise linear interpolation, see a discussion
>"Graph look up" in .excel.charting. You can search the google.com
>archives of the XL newsgroups for a post by Dave Braden for code based
>on cubic splines and visit www.xlrotor.com for code based on Bezier
>curves.

Of course there are ways to do it. It's just that they're bulky and
nonintuitive. There are ways to calculate depreciation using only the
arithmetic functions and lots of cells for intermediate calculations.
Why does Excel include DB, DDB, SLN, SYD and VDB functions?

Your argument is flawed.

As nice as it would be for MS to meet every need for every function
from every customer, XL is flexible enough to allow one to add new
capabilities.

For a few options for piecewise linear interpolation, see a discussion
"Graph look up" in .excel.charting. You can search the google.com
archives of the XL newsgroups for a post by Dave Braden for code based
on cubic splines and visit www.xlrotor.com for code based on Bezier
curves.


--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article <[email protected]>, =?Utf-
8?B?RGFuIEdhdXRoaWVy?= <Dan [email protected]> says...
> Please add this function which may be used either for a vector set of data or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions
>

Which you can do with LINEST etc. or more directly with TREND or
FORECAST by including just the relevant surrounding points (instead of
the entire data set) for a given interpolation.

Jerry

MrShorty wrote:

> I would agree with the OP on this one. LINEST etc. are curve fitting
> functions, not interpolating functions. Sometimes when you have a
> table of data, it is easier/preferable to approximate the function as a
> series of straight lines connecting the data points (similar to what a
> line chart/XY chart does) rather than attempt to fit the data to a
> curve.

Tushar Mehta wrote...
>As nice as it would be for MS to meet every need for every function
>from every customer, XL is flexible enough to allow one to add new
>capabilities.

The logical implications of this argument are that because Excel is
extensible in terms of functions, Microsoft need never add another.

As for meeting needs, when was the last time anyone who uses Excel
regularly needed any of the 3 Bessel functions? And for those who
do need Bessel functions, it would have been nice if Microsoft had
allowed for fractional parameters.

Linear interpolation is a commonly needed bit of functionality. Not,
it'd seem, as frequently requested as summing cells by color or font
attributes, but much more common than finding solutions to
cylindrical harmonics.

It'd be good for Microsoft to add some built-in functions to Excel.
But, if you're going to be an absolutist about this (denying the need
or usefullness of any more functions), perhaps we could discuss new
capabilities that would make Excel *MORE* *CONSISTENT*.

Top of my list would be rewriting the formula parser (which probably
hasn't been touched since Excel 4) to accept nested function calls
more than 7 levels deep. As I've pointed out several times, Excel has
no trouble calculating such formulas, but it won't allow them to be
created or edited. How can they be? They can be created by other,
non-Microsoft spreadsheets, saved in .XLS format (so the file format
in addition to the recalc engine isn't the problem here), and opened
in Excel. Would that be a useful new feature?

>For a few options for piecewise linear interpolation, see a discussion
>"Graph look up" in .excel.charting. You can search the google.com
>archives of the XL newsgroups for a post by Dave Braden for code based
>on cubic splines and visit www.xlrotor.com for code based on Bezier
>curves.

Of course there are ways to do it. It's just that they're bulky and
nonintuitive. There are ways to calculate depreciation using only the
arithmetic functions and lots of cells for intermediate calculations.
Why does Excel include DB, DDB, SLN, SYD and VDB functions?

Your argument is flawed.

As nice as it would be for MS to meet every need for every function
from every customer, XL is flexible enough to allow one to add new
capabilities.

For a few options for piecewise linear interpolation, see a discussion
"Graph look up" in .excel.charting. You can search the google.com
archives of the XL newsgroups for a post by Dave Braden for code based
on cubic splines and visit www.xlrotor.com for code based on Bezier
curves.


--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article <[email protected]>, =?Utf-
8?B?RGFuIEdhdXRoaWVy?= <Dan [email protected]> says...
> Please add this function which may be used either for a vector set of data or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions
>

Which you can do with LINEST etc. or more directly with TREND or
FORECAST by including just the relevant surrounding points (instead of
the entire data set) for a given interpolation.

Jerry

MrShorty wrote:

> I would agree with the OP on this one. LINEST etc. are curve fitting
> functions, not interpolating functions. Sometimes when you have a
> table of data, it is easier/preferable to approximate the function as a
> series of straight lines connecting the data points (similar to what a
> line chart/XY chart does) rather than attempt to fit the data to a
> curve.

Bernard Liengme wrote...
>You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
>from there.
....

LINEST would be gross overkill. Besides, FORECAST and TREND would be
far easier than any of these. The problem is that using it to
interpolate in a table (TBL) for a value (v) involves expressions like

TREND(OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),YvalCol-1,2,1),
OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),XvalCol-1,2,1),v)

You may like these, but they are a bit long. When they're general like
this, they eat 3 levels of nested function calls. A simpler approach
would be handy, but I suspect we won't see it in Excel until a few
months after Hell organizes an Ice Hockey league.

You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
from there.
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Dan Gauthier" <Dan [email protected]> wrote in message
news:[email protected]...
> Please add this function which may be used either for a vector set of data
> or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow
> this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions

As nice as it would be for MS to meet every need for every function
from every customer, XL is flexible enough to allow one to add new
capabilities.

For a few options for piecewise linear interpolation, see a discussion
"Graph look up" in .excel.charting. You can search the google.com
archives of the XL newsgroups for a post by Dave Braden for code based
on cubic splines and visit www.xlrotor.com for code based on Bezier
curves.


--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article <[email protected]>, =?Utf-
8?B?RGFuIEdhdXRoaWVy?= <Dan [email protected]> says...
> Please add this function which may be used either for a vector set of data or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions
>

Which you can do with LINEST etc. or more directly with TREND or
FORECAST by including just the relevant surrounding points (instead of
the entire data set) for a given interpolation.

Jerry

MrShorty wrote:

> I would agree with the OP on this one. LINEST etc. are curve fitting
> functions, not interpolating functions. Sometimes when you have a
> table of data, it is easier/preferable to approximate the function as a
> series of straight lines connecting the data points (similar to what a
> line chart/XY chart does) rather than attempt to fit the data to a
> curve.

Tushar Mehta wrote...
>As nice as it would be for MS to meet every need for every function
>from every customer, XL is flexible enough to allow one to add new
>capabilities.

The logical implications of this argument are that because Excel is
extensible in terms of functions, Microsoft need never add another.

As for meeting needs, when was the last time anyone who uses Excel
regularly needed any of the 3 Bessel functions? And for those who
do need Bessel functions, it would have been nice if Microsoft had
allowed for fractional parameters.

Linear interpolation is a commonly needed bit of functionality. Not,
it'd seem, as frequently requested as summing cells by color or font
attributes, but much more common than finding solutions to
cylindrical harmonics.

It'd be good for Microsoft to add some built-in functions to Excel.
But, if you're going to be an absolutist about this (denying the need
or usefullness of any more functions), perhaps we could discuss new
capabilities that would make Excel *MORE* *CONSISTENT*.

Top of my list would be rewriting the formula parser (which probably
hasn't been touched since Excel 4) to accept nested function calls
more than 7 levels deep. As I've pointed out several times, Excel has
no trouble calculating such formulas, but it won't allow them to be
created or edited. How can they be? They can be created by other,
non-Microsoft spreadsheets, saved in .XLS format (so the file format
in addition to the recalc engine isn't the problem here), and opened
in Excel. Would that be a useful new feature?

>For a few options for piecewise linear interpolation, see a discussion
>"Graph look up" in .excel.charting. You can search the google.com
>archives of the XL newsgroups for a post by Dave Braden for code based
>on cubic splines and visit www.xlrotor.com for code based on Bezier
>curves.

Of course there are ways to do it. It's just that they're bulky and
nonintuitive. There are ways to calculate depreciation using only the
arithmetic functions and lots of cells for intermediate calculations.
Why does Excel include DB, DDB, SLN, SYD and VDB functions?

Your argument is flawed.

Bernard Liengme wrote...
>You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
>from there.
....

LINEST would be gross overkill. Besides, FORECAST and TREND would be
far easier than any of these. The problem is that using it to
interpolate in a table (TBL) for a value (v) involves expressions like

TREND(OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),YvalCol-1,2,1),
OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),XvalCol-1,2,1),v)

You may like these, but they are a bit long. When they're general like
this, they eat 3 levels of nested function calls. A simpler approach
would be handy, but I suspect we won't see it in Excel until a few
months after Hell organizes an Ice Hockey league.

You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
from there.
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Dan Gauthier" <Dan [email protected]> wrote in message
news:[email protected]...
> Please add this function which may be used either for a vector set of data
> or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow
> this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions

Which you can do with LINEST etc. or more directly with TREND or
FORECAST by including just the relevant surrounding points (instead of
the entire data set) for a given interpolation.

Jerry

MrShorty wrote:

> I would agree with the OP on this one. LINEST etc. are curve fitting
> functions, not interpolating functions. Sometimes when you have a
> table of data, it is easier/preferable to approximate the function as a
> series of straight lines connecting the data points (similar to what a
> line chart/XY chart does) rather than attempt to fit the data to a
> curve.

As nice as it would be for MS to meet every need for every function
from every customer, XL is flexible enough to allow one to add new
capabilities.

For a few options for piecewise linear interpolation, see a discussion
"Graph look up" in .excel.charting. You can search the google.com
archives of the XL newsgroups for a post by Dave Braden for code based
on cubic splines and visit www.xlrotor.com for code based on Bezier
curves.


--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article <[email protected]>, =?Utf-
8?B?RGFuIEdhdXRoaWVy?= <Dan [email protected]> says...
> Please add this function which may be used either for a vector set of data or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions
>

Tushar Mehta wrote...
>As nice as it would be for MS to meet every need for every function
>from every customer, XL is flexible enough to allow one to add new
>capabilities.

The logical implications of this argument are that because Excel is
extensible in terms of functions, Microsoft need never add another.

As for meeting needs, when was the last time anyone who uses Excel
regularly needed any of the 3 Bessel functions? And for those who
do need Bessel functions, it would have been nice if Microsoft had
allowed for fractional parameters.

Linear interpolation is a commonly needed bit of functionality. Not,
it'd seem, as frequently requested as summing cells by color or font
attributes, but much more common than finding solutions to
cylindrical harmonics.

It'd be good for Microsoft to add some built-in functions to Excel.
But, if you're going to be an absolutist about this (denying the need
or usefullness of any more functions), perhaps we could discuss new
capabilities that would make Excel *MORE* *CONSISTENT*.

Top of my list would be rewriting the formula parser (which probably
hasn't been touched since Excel 4) to accept nested function calls
more than 7 levels deep. As I've pointed out several times, Excel has
no trouble calculating such formulas, but it won't allow them to be
created or edited. How can they be? They can be created by other,
non-Microsoft spreadsheets, saved in .XLS format (so the file format
in addition to the recalc engine isn't the problem here), and opened
in Excel. Would that be a useful new feature?

>For a few options for piecewise linear interpolation, see a discussion
>"Graph look up" in .excel.charting. You can search the google.com
>archives of the XL newsgroups for a post by Dave Braden for code based
>on cubic splines and visit www.xlrotor.com for code based on Bezier
>curves.

Of course there are ways to do it. It's just that they're bulky and
nonintuitive. There are ways to calculate depreciation using only the
arithmetic functions and lots of cells for intermediate calculations.
Why does Excel include DB, DDB, SLN, SYD and VDB functions?

Your argument is flawed.

Bernard Liengme wrote...
>You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
>from there.
....

LINEST would be gross overkill. Besides, FORECAST and TREND would be
far easier than any of these. The problem is that using it to
interpolate in a table (TBL) for a value (v) involves expressions like

TREND(OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),YvalCol-1,2,1),
OFFSET(TBL,MATCH(v,INDEX(TBL,0,XvalCol)),XvalCol-1,2,1),v)

You may like these, but they are a bit long. When they're general like
this, they eat 3 levels of nested function calls. A simpler approach
would be handy, but I suspect we won't see it in Excel until a few
months after Hell organizes an Ice Hockey league.

You have SLOPE, INTERCEPT and LINEST, making an interpolation is rather easy
from there.
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Dan Gauthier" <Dan [email protected]> wrote in message
news:[email protected]...
> Please add this function which may be used either for a vector set of data
> or
> for a 2 dimensional array of data.
>
> ----------------
> This post is a suggestion for Microsoft, and Microsoft responds to the
> suggestions with the most votes. To vote for this suggestion, click the "I
> Agree" button in the message pane. If you do not see the button, follow
> this
> link to open the suggestion in the Microsoft Web-based Newsreader and then
> click "I Agree" in the message pane.
>
> http://www.microsoft.com/office/comm...heet.functions

Please add this function which may be used either for a vector set of data or
for a 2 dimensional array of data.

----------------
This post is a suggestion for Microsoft, and Microsoft responds to the
suggestions with the most votes. To vote for this suggestion, click the "I
Agree" button in the message pane. If you do not see the button, follow this
link to open the suggestion in the Microsoft Web-based Newsreader and then
click "I Agree" in the message pane.

http://www.microsoft.com/office/comm...heet.functions