Message Boards Message Boards

0
|
18758 Views
|
14 Replies
|
2 Total Likes
View groups...
Share
Share this post:

Why doesn't Quantity[] and related functions work for me?

I'm a new user of MMA ver. 10.3.0 Home Edition. I'm trying to learn how to use Units, but it's not working. For example

In[47]:= UnitConvert[Quantity[12, "Meters"/"Seconds"], "Miles"/"Hours"]

Out[47]= UnitConvert[
 QuantityUnits`Private`ToQuantity[
  QuantityUnits`Private`UnknownQuantity[12, ("Meters")/(
   "Seconds")]], ("Miles")/("Hours")]

If I load the Units` package I get the answer I seek:

In[48]:= << Units`

Convert[12  Meter/Second, Mile/Hour]

Out[49]= (37500 Mile)/(1397 Hour)

But starting with ver 9 I shouldn't have had to do that. Any ideas about what's going on?
POSTED BY: Victor Bloomfield
14 Replies
Sort By:

I often see this problem where units stop working but I have not been able to produce a sequence of commands to reproduce it. However, I have found this commands fixes the issue:

<<QuantityUnitsLoader`

This does not prevent the issue from hapening again in the future but at least fixes it when it happens.
POSTED BY: Gustavo Delfino
Dana DeLouis
Dana DeLouis
Posted 9 years ago

Hi. It sounds like your version is working. What I had to do for the Mac, and it appears to work, was the following...

Get["EntityFramework`"]

However, entering that command now doesn't seem to do anything for me at the moment. Perhaps it is because it's working. Perhaps when it was broken/missing, it triggered a refresh. I don't know.

Then, when I entered the following, it rebuilt the data interface.

EntityValue[]

Support told me they are aware of the issue, at least for the Mac. I'm not sure of Windows versions.
POSTED BY: Dana DeLouis

Thanks, that's helpful. I've got the Units stuff working OK now, but I was playing around with sounds (Play, EmitSound, etc.) and had to quit and restart MMA before it would actually make noise. At one point in the process, just as with Units, it appeared that something was being loaded from the Wolfram site. On the other hand, the few Entity things that I've tried from the Help examples (e.g., Entity["Mythology"]["Properties"]) have worked OK.

How do you reset Paclet data? Via PacletUpdate, or ...?

POSTED BY: Victor Bloomfield
Dana DeLouis
Dana DeLouis
Posted 9 years ago
POSTED BY: Dana DeLouis
POSTED BY: David Reiss

"Any port in a storm." I'm glad it's working now!
POSTED BY: David Reiss
POSTED BY: Victor Bloomfield

For some reason, the old behavior of the Units package no longer persists after I did what I described. Convert[ ] no longer is recognized as a function, but UnitConvert[ ] now is. So I think that the automatic(?) upload from the Wolfram site, triggered by the restart after addition to the init.m file, updated the program properly.
POSTED BY: Victor Bloomfield
POSTED BY: Victor Bloomfield
POSTED BY: David Reiss
POSTED BY: David Reiss
POSTED BY: David Reiss

That seems to have done the trick. Thanks.
POSTED BY: Victor Bloomfield

I don't know the reason why it does not work by default. The code you posted works fine for my Mathematica. However if you'd like to work it around, editing the init.m file in C:\ProgramData\Mathematica\Kernel should do the trick. Simply add 

Needs["Units`"]

at the end of the file.
POSTED BY: Wojciech Artichowicz
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Tag limit exceeded
Note: Only the first five people you tag will receive an email notification; the other tagged names will appear as links to their profiles.
Reply Preview
Attachments
Remove
or Discard

Group Abstract Group Abstract