# Tagged Questions

Questions about using, converting, or interpreting units of measurement in Mathematica.

262 views

### Why cant Mathematica 9 interpret this unit?

I'm using Mathematica 9.0.1. Sorry for using an image, but pasting code messed up the output formatting. I'd like to represent 25 Btu/(hr ft F). All units are spelled correctly as identified in ...
152 views

### Is it possible to use Gaussian cgs units in $Mathematica$ computations?

I was trying to do computations in Gaussian cgs units, and of course I failed due to dimensional issues. For instance, $q_1 q_2/r$ cannot be converted to $\mathrm{erg}$ since Gaussian system uses \$4\...
529 views

### Problem in units convertion when multipliying Boltzmann constant and a temperature

When define the temperature of a variable in Celsius, Mathematica 9.0 does not calculate the right answer when multiplying by boltzmann constant. Example: ...
276 views

### Can't force UnitConvert to be evaluated in Plot

I'm trying to use new units support in Mathematica 9. When I Plot Quantity functions everything is OK. ...
220 views

### Moles/Liters doesn't get simplified to Molar even though Molar*Liters gets simplified to Moles

Why can't Mathematica 9 simplify mol/L to M, when it can simplify M*L to mol? ...
471 views

### Why doesn't Mathematica divide out the Kelvins?

I thought I understood Mathematica V9 units. However, I can't get these numbers to plot, or even to come out to a nice clean unit of mass (say grams). The Kelvin's ...
108 views

### Extract function parameters from “unevaluated” FormBox

I want to get the abbreviation for a Unit from its full name eg. "Newtons" => "N". Using <...
124 views

### Insert a Quantity Unit literal in TraditionalForm

Is there a keyboard shortcut for creating something like the result of this: Quantity["Kilograms" * ("Meters")^2 / ("Seconds")^2] After copying the result to a <...
1k views

### Units, plotting and empty plots

maybe I'm completely newbie but I can't understand the behavior of units and the command plot. I'm doing some easy plotting of the state equation for gasses: ...
78 views

### Will aliasing the Quantity and UnitConvert functions to “in” and “to” create problems?

It seems that there is a lot of interest in enhancing the use of units in Mathematica; various solutions in the name of brevity, correctness, and general utility have been demonstrated. I've begun ...
125 views

### How can I say that all quantities need to be positive (and real)? [duplicate]

Can you say at the beginning of a script in Mathematica that you want all the quantities to be positive (and real)? So that in all calculations, only the real values of these quantities will be ...
200 views

### Quantity and Trig functions

I have a bunch of data to which I've assigned units using Quantity, including some angular measurements in degrees. I'd like to be able to use these measurements ...
80 views

### List of supported units in Mathematica 9 [duplicate]

Is there a list of supported units in Mathematica 9 documentation? I personal haven't found any; even the physical constants (newly supported as units in 9) can only be found in compatibility ...
478 views

### How do I seamlessly migrate from the older Units package to Mathematica 9's Quantity objects?

I have several notebooks that make use of the Units package and would like to be able to work simultaneously with the older units and ...
2k views

### Plotting with Units

I'm trying to get Mathematica to plot with units, but I'm having some trouble. Below is a minimal example of trying to plot y = x, where ...
703 views

### Kelvin per Kelvin Difference

Bug introduced in 9 and partially persists through 10.2 or later The specific bug described in the original question is fixed ("Kelvin" is correctly recognized as <...
291 views

### How to deal with units in logarithms?

I'm trying to take a formula, take it's integral which yields a formula with logarithms, and then directly plug in values with units and get an answer. However if the units go into any of the ...
1k views

### Built-in unit strings recognized by Quantity?

It’s great that Quantity can utilize Wolfram Alpha to interpret unit strings that it doesn’t recognize, but I need my code to work on machines that do not have ...
172 views

### NumberForm and units

NumberForm can be used to print Quantities to a specified precision. For example, x=Quantity[5.123456789,"Meters"]; 5.12346 m Print[NumberForm[x,{4,2}]] 5.12 m ...
339 views

### Cannot plot Quantity values with DateListPlot

Is there a way to use DateListPlot with Quantity values? I retrieved the following time series data from WolframAlpha: ...
392 views

### Incomplete implementation of units?

I've been playing around with the new units capability in MMA9 and I'm becoming a bit frustrated with what I perceive as an incomplete implementation of this capability and I'm wondering if there are ...
2k views

### Is there a “No Units” (i.e., dimensionless) unit?

I would like to be able to call the Quantity function with a null unit so that it returns the original dimensionless value. For example, ...
738 views

### Unit issues in Mathematica 9

I posted the following on the Google+ group comp.soft-sys.math.mathematica and had no luck with responses. I've done a Google search and, to the best of my ability, ...
3k views

### Are Mathematica 9 and 10 units really slow?

This generates 75 unitized pairs for a plot that displays physical units: ...
369 views

### Getting all physical units with prefixes

How we can get the list with all physical units and prefixes from WolframAlpha and make symbols from the result to be equal their corresponding quantities like described in this post?
269 views

### Where is the unit after a calculation?

I was playing with some of the new features, and when I type e.g. Quantity[10, "ml"] + Quantity[250 - 100, "ml"] I get ...
831 views

### Simplifying to different units

Is there a way to force Mathematica to UnitSimplify to a different unit? For example, I would like kg m^2/s^2 to simplify to <...
260 views

### Inputting abbreviated units [duplicate]

Possible Duplicate: Simpler input for the new unit support Is there a way to input abbreviated units directly from the keyboard? One can get a value with abbreviated units through the Wolfram/...
1k views

### Use of own unit abbreviations

I have been using AutomaticUnits in my calculations. In this package all I had to do was to declare the units I wanted e.g. mm, kN, sec, kPa, litres etc. in terms of existing units, and then use them ...
576 views

### Should 0 * 5ft be 0 or 0ft?

After playing with the new quantity system in Mathematica 9 for a while, I keep stumbling over this issue: 0 * Quantity[1, "Meters"] is not the same as ...
1k views

### Implementing CGS unit system in Mathematica 9

So I've just installed the trial version of Mathematica 9. The first noticeable feature for me is the new built-in physical units. I used AutomaticUnits package ...