Timeline for Indexed Thread on dataset and list
Current License: CC BY-SA 3.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 5, 2015 at 18:13 | comment | added | alancalvitti |
@WReach, that's a troublesome design, though to be fair, if the power of Dataset is like that of a new language interface is probably worth the tradeoff vs openness & breaking EIAE = Everything Is An Expression.
|
|
| Feb 5, 2015 at 18:09 | comment | added | alancalvitti |
@Mr.Wizard, thanks, edited. 10.0.3 will be the release that fixes Dataset and also casts all the world's data to WDF.
|
|
| Feb 5, 2015 at 18:07 | history | edited | alancalvitti | CC BY-SA 3.0 |
edited body
|
| Feb 5, 2015 at 16:58 | comment | added | WReach |
@soandos An evaluation leak is a type of bug where a function evaluates an expression that should remain unevaluated. In the current example, the expression First@#2 is part of a function body and should not be evaluated until that function is called. Unfortunately, the type system accidentally evaluates that expression prematurely while trying to identify the type of the expression. This causes the message we see.
|
|
| Feb 5, 2015 at 16:22 | comment | added | soandos | @WReach What is an "evaluation leak"? | |
| Feb 5, 2015 at 8:18 | comment | added | Mr.Wizard | Are you a beta tester for 10.0.3 or is that a typo? | |
| Feb 5, 2015 at 5:24 | comment | added | WReach |
+1 We can dodge the warning message in 10.0.2 using something like ds[MapThread[Append[#, "age" -> #2 ] &, {#, ages}] &]. Messages like this are due to some serious evaluation leaks in the 10.0.2 type system code :(
|
|
| Feb 5, 2015 at 5:04 | vote | accept | soandos | ||
| Feb 5, 2015 at 5:04 | comment | added | soandos | ah, got it. Thank you. | |
| Feb 5, 2015 at 5:03 | comment | added | alancalvitti |
MapIndexed works on multidimensional arrays. MapIndexed[f, ages] gives {f[1, {1}], f[2, {2}]}. If ages were, say, a 2-dim array, then the indexes would be {i,j}. In this problem, First picks out the rows of ages.
|
|
| Feb 5, 2015 at 4:58 | comment | added | soandos |
Do you mind explaining how this works? What is the First function doing (I understand the rest)
|
|
| Feb 5, 2015 at 4:55 | history | answered | alancalvitti | CC BY-SA 3.0 |