How to Make a Double Lookup

[Libbya]

Double lookups are so darn useful and slightly tricky to make so I figured I'd make a screencast in a dedicated thread that shows exactly how to make one and how to select each of the tables.

[Libbya]

Double lookups are so darn useful and slightly tricky to make so I figured I'd make a screencast in a dedicated thread that shows exactly how to make one and how to select each of the tables.

[Libbya]

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@ed57gmc wrote:

I found a similar way to do 2 lookups, but with one Lookup. You can add multiple parameters to a single lookup action. This also provides the ability to do asymmetrical lookups. For example, in the attached block, I have Width (X) and Height (Y) stretch parameters. With 2 lookups, selecting a value changes the height and width using the same value, i.e. a square. But with the lookup in this sample, I can implement a table with x and y of different values.

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What you posted is just basic single-lookup functionality.  Single lookups are certainly powerful items, but that are very well documented and their discussion is off-topic in this thread.  This thread is about double lookups and you might have missed the huge added functionality that double lookups offer over single lookups.  

[Libbya]

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@ed57gmc wrote:

I found a similar way to do 2 lookups, but with one Lookup. You can add multiple parameters to a single lookup action. This also provides the ability to do asymmetrical lookups. For example, in the attached block, I have Width (X) and Height (Y) stretch parameters. With 2 lookups, selecting a value changes the height and width using the same value, i.e. a square. But with the lookup in this sample, I can implement a table with x and y of different values.

---

What you posted is just basic single-lookup functionality.  Single lookups are certainly powerful items, but that are very well documented and their discussion is off-topic in this thread.  This thread is about double lookups and you might have missed the huge added functionality that double lookups offer over single lookups.  

[ed57gmc]

@Libbya wrote:

What you posted is just basic single-lookup functionality.  Single lookups are certainly powerful items, but that are very well documented and their discussion is off-topic in this thread.  This thread is about double lookups and you might have missed the huge added functionality that double lookups offer over single lookups.

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I guess in my line of work I haven't come across a need for double lookup. Can you post an example block?

[ed57gmc]

@Libbya wrote:

What you posted is just basic single-lookup functionality.  Single lookups are certainly powerful items, but that are very well documented and their discussion is off-topic in this thread.  This thread is about double lookups and you might have missed the huge added functionality that double lookups offer over single lookups.

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I guess in my line of work I haven't come across a need for double lookup. Can you post an example block?

[Libbya]

I have posted examples in many threads on this forum.  

[Libbya]

I have posted examples in many threads on this forum.  

[Jaycee.foli]

I would love to see a tutorial that explains the "why" behind lookups, rather than just the how. I have used a double lookup twice before, but always as  "do this" from someone else, without explanation as to why this method is the way to go. I think it would be greatly beneficial to many of us middle of the road users to increase our knowledge and skills. If you have any materials or videos that do this, please share. It would be greatly appreciated.

[Jaycee.foli]

I would love to see a tutorial that explains the "why" behind lookups, rather than just the how. I have used a double lookup twice before, but always as  "do this" from someone else, without explanation as to why this method is the way to go. I think it would be greatly beneficial to many of us middle of the road users to increase our knowledge and skills. If you have any materials or videos that do this, please share. It would be greatly appreciated.

[j.palmeL29YX]

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@Jaycee.foli wrote:

... the "why" behind [Double] lookups, 

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I'd suggest, analyze some  of the block examples which use Double Lookups and then try to get the same functionality without using a Double Lookup. I think this way your question will answer itselfe. 

[j.palmeL29YX]

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@Jaycee.foli wrote:

... the "why" behind [Double] lookups, 

---

I'd suggest, analyze some  of the block examples which use Double Lookups and then try to get the same functionality without using a Double Lookup. I think this way your question will answer itselfe. 

[Libbya]

The concept on how they function is relatively simple.  

With a single lookup, when the user selects a different row on the lookup table either through the grip or through properties, the block parameters that are added to the table are changed to match their values for that row of the lookup table.

A double lookup behaves in a similar manner, but instead of the user selecting a row of the table, when the values of the parameters listed on one table all match a row, the row is selected and the parameters that are added to the other table are changed to match their values for that row of the lookup table.

When the above is understood, the 'why' becomes relatively obvious.  It allows some parameter values to be forced when other parameter values match specific block states.  

[Libbya]

The concept on how they function is relatively simple.  

With a single lookup, when the user selects a different row on the lookup table either through the grip or through properties, the block parameters that are added to the table are changed to match their values for that row of the lookup table.

A double lookup behaves in a similar manner, but instead of the user selecting a row of the table, when the values of the parameters listed on one table all match a row, the row is selected and the parameters that are added to the other table are changed to match their values for that row of the lookup table.

When the above is understood, the 'why' becomes relatively obvious.  It allows some parameter values to be forced when other parameter values match specific block states.  

[Jaycee.foli]

So basically, one look-up makes certain parameters active, and the second look-up tells the first which parameters to make active based on how the current active parameters are set, via the grips for instance? Is that the basic idea?

[Jaycee.foli]

So basically, one look-up makes certain parameters active, and the second look-up tells the first which parameters to make active based on how the current active parameters are set, via the grips for instance? Is that the basic idea?

[h_s_walker]

Yep that's the basic idea

[h_s_walker]

Yep that's the basic idea

[Gil_C]

Now that is really cool. I wonder if you can do it with visibility state. I am thing not, but going to try it on Monday.

[Gil_C]

Now that is really cool. I wonder if you can do it with visibility state. I am thing not, but going to try it on Monday.

[zobb011111]

To make a double lookup in Excel, follow these steps:

1. Set Up Data: Organize your data in a table format.

2. Create Dropdowns:
- Select cells for category and topic selection.
- Use `Data Validation` to create dropdowns for these cells.

3. Find Row and Column
- Use `MATCH` to find the row for the selected category and topic.
- Use `MATCH` to find the column for the data header.

4. Combine `INDEX` and `MATCH`
- Use `INDEX` to get the value based on the found row and column.

### Example Formula
Assume category is in `E1`, topic in `F1`:

```excel
=INDEX(C:D, MATCH(E1, A:A, 0), MATCH("Data 2A", 1:1, 0))
```

This formula retrieves the value by combining `INDEX` and `MATCH` functions.

[zobb011111]

To make a double lookup in Excel, follow these steps:

1. Set Up Data: Organize your data in a table format.

2. Create Dropdowns:
- Select cells for category and topic selection.
- Use `Data Validation` to create dropdowns for these cells.

3. Find Row and Column
- Use `MATCH` to find the row for the selected category and topic.
- Use `MATCH` to find the column for the data header.

4. Combine `INDEX` and `MATCH`
- Use `INDEX` to get the value based on the found row and column.

### Example Formula
Assume category is in `E1`, topic in `F1`:

```excel
=INDEX(C:D, MATCH(E1, A:A, 0), MATCH("Data 2A", 1:1, 0))
```

This formula retrieves the value by combining `INDEX` and `MATCH` functions.