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

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2
votes
2answers
181 views

Calculations with physical units [closed]

I really don’t get the Units in Mathematica 9. to work. I have tried this in the past for several times and at the end always run into some troubles. For example ...
2
votes
2answers
256 views

How to specify units for ImageSize Option? [duplicate]

I'm trying out making a CDF and I want it to print within the margins of Letter paper. There is an ImageSize option that I would like to set; some plots will be in ...
2
votes
1answer
49 views

Integrate complains about incompatible quantities in integration limits

When I run the following code, Integrate throws ...
2
votes
1answer
224 views

UnitSimplify returns unexpected non-SI unit combination

I am trying to get units working in mathematica in the following expression for diffusion: $D = {K_B T}/{3 \pi \eta L}$ My code is as follows: ...
2
votes
2answers
835 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 ...
2
votes
1answer
74 views

How do I extract units from an expression

I need to take the units off of this expression: (5 Coulomb)/(6 Second) In order to do some unit simplification. Is there any way to do this? I have tried Case, but could not get it to work ...
2
votes
1answer
87 views

Physical quantities to decimal power

How can I get Mathematica to properly simplify physical quantities with dimensions to decimal power, such as $1 \frac{1}{\text{s}^{0.7}}\text{dynes}\text{/(}\text{cm}^2\text{Pa})$ that should simplify ...
2
votes
1answer
106 views

How do you get a country's GDP per capita in Euros?

Right now, I'm getting the data in U.S. Dollars and converting it to Euros like this: ...
2
votes
4answers
157 views

Cancelling units in two-argument ArcTan

Consider ArcTan[3, -3] (* out: *) -Pi/4 ArcTan[3 a Sin[t/2], -3 a Sin[t/2]] (* out: *) ArcTan[3 a Sin[t/2], -3 a Sin[t/2]] However, we can fix the ...
2
votes
1answer
36 views

MixedRadix rounds incorrectly

You can Round Quantitys. For example, how many inches are in a meter? ...
2
votes
1answer
60 views

QuantityVariable usage

When I try to run the following code, Mathematica gives me an error message: "Solve was unable to determine the units of quantities that appear in the input." ...
2
votes
1answer
121 views

Using Manipulate[ ] with physical units

I'm a new user, and am trying to build a simple Boyle's law system in Mathematica. I want to include the units of the values, as I may need to perform some conversions later. If my quantities are a ...
2
votes
1answer
123 views

Converting in various currencies

I was just playing around with Mathematica converting some currencies: ...
2
votes
0answers
29 views

TimeSeriesInsert issue with Quantity expressions

This first sample code works as expected: ...
2
votes
0answers
83 views

Quantities formatting problem

So I've developed this simple code ...
2
votes
0answers
115 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 ...
2
votes
0answers
79 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 ...
1
vote
3answers
132 views

Inconsistent units? [closed]

I have reviewed this statement until my eyes hurt; can someone tell me why the units output aren't lb/ft^2? ...
1
vote
1answer
109 views

UnitConvert to Electronvolts returns Electronvolts/Moles [closed]

The question is probably clear from the title. When I want to convert a kinetic energy, that contains the Molar Gas-Constant into Electronvolts I get eV/mol. ...
1
vote
1answer
50 views

Simplify CubeRoot of meter cubes

Why Mathematica doesn't simplify CubeRoot of meter cubes to meters? r = Quantity[10, "Meters"]; v = 4/3 r^3 Pi; CubeRoot[% * 3/4 / Pi] returns ...
1
vote
1answer
43 views

UnitConvert bar <-> Pa

I wanted to use the following unit cMax = Quantity[6.8221*^-9, "L/s/bar"]; But when calculating with it, I recognised there is some strange behaviour. So I tried ...
1
vote
1answer
163 views

Solving equations with QuantityVariable

I'm trying to understand how to easily solve equations that use QuantityVariable. Why does this fail? ...
1
vote
1answer
1k 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 ...
1
vote
1answer
92 views

Changed appearance of Quantity expressions in v10.1.0

After installing Mathematica v10.1.0 (in Windows 8.1 x64), I noticed a change in appearance of Quantity expressions. For example under Mathematica v10.1.0: while ...
1
vote
1answer
496 views

Unit of the frequency axis in BodePlot

I have a simple question: What is the unit of the frequency axis in the BodePlot? I searched the documentation, but only found this: The scaling functions can be specified as ...
1
vote
1answer
121 views

Caching data in Mathematica package

Consider the following: m=Quantity[1,"meter"] If I run the package, it will return 1m But when I load the package, the ...
1
vote
1answer
103 views

Extract function parameters from “unevaluated” FormBox

I want to get the abbreviation for a Unit from its full name eg. "Newtons" => "N". Using ...
1
vote
1answer
89 views

AutomaticUnits in WM10

Despite the unit improvement in WM10, I am still a big fan of the AutomaticUnits package, as I find it faster and more elegant to work with. However, it seems to be ...
1
vote
1answer
51 views

UnitConvert of a Quantity whose value is a function of a Quantity

I am having trouble with UnitConvert when the QuantityMagnitude contains an embedded ...
1
vote
1answer
83 views

Unit System documentation

Is there any documentation on what consists of the unit system "SIBase","Imperial", "SI" and ...
1
vote
1answer
96 views

Grouping units more sanely

Would it be possible to get Mathematica to group units more sanely. For example the calculation: ...
1
vote
0answers
22 views

Using Infinity with AutomaticUnits

I am using the AutomaticUnits package in Mathematica 10, and I am writing some unit checking functions. However, I run into a problem when I have an Infinity, since ...
1
vote
0answers
41 views

Using Quantity[] units causes errors in my calculation

I have an interpolation function in which I wish to use actual units. If I perform the calculation normally, it works fine and returns a proper FittedModel. To illustrate my problem, consider the ...
1
vote
0answers
43 views

Inequality involving Quantity stays unevaluated

Mathematica 10.1.0, Windows 8.1 x64 An expression like this one a < x < b is represented as Less[a, x, b] while ...
1
vote
1answer
69 views

Can I convert a list of units to a different base set?

I have a list of quantities with varying units (a short example list is shown below): ...
1
vote
0answers
80 views

Geodesy without units?

Suppose I'm interested in the latitude of Los Angeles and I do the following: ...
1
vote
0answers
99 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 ...
1
vote
0answers
73 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 ...
1
vote
0answers
123 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 ...
0
votes
2answers
78 views

Converting the units of an equation or expression (how to become 3 times heavier…)

(THIS QUESTION HAD A MAJOR SIMPLIFICATION EDIT) Lets suppose I want to convert the falling body equation, from one set of units to another. I start with: ...
0
votes
1answer
105 views

AstronomicalData not including units?

I like using mathematica to do my physics homework, and AstronomicalData is useful for that, but it doesn't seem to work properly with units. [the question is, at ...
0
votes
1answer
57 views

Working with symbolic values in Quantities [duplicate]

I have the following expression: x Quantity[y, ("Milliwatts"*"Seconds"^2)/"Joules"] If I try to convert this to the SI unit, I would expect to get ...
0
votes
1answer
139 views

Unit conversion is not simplifying units

I'm running into what looks like an error. ...
0
votes
1answer
88 views

NIntegrate with units: unable to determine the units of quanitites that appear in the input

I want to integrate Planck's law of radiation in a certain wavelength intervall with units. I define some constants: ...
0
votes
0answers
16 views

QuantityArray display and UnitConvert

In the reference: But if you try (Mathematica 10.1 Windows 8.1 x84): qa = QuantityArray[{2.3, 1.5, 9.0}, "Meters"]
0
votes
0answers
65 views

Mathematica 10.1 doesn't recognize “Events” unit

Today's Wolfram blog post inspired me to play with the TemporalData and MovingMap features, and in the process of doing so, I ...
0
votes
0answers
65 views

Plotting Earth's position with units

I'm trying to plot the Earth position with the Sun in the origin. I have two lists like this: ...
0
votes
0answers
36 views

Why numerical functions can't digest InterpolatingFunction with units?

Answering this question gave me the idea that I must be missing something.. In brief, numerical functions generally 'understand' units: ...
0
votes
0answers
117 views

Meaning of backtick in conjunction with units [duplicate]

In this fragment from an equation solution the backtick is used twice: ...
-1
votes
1answer
111 views

Make Quantity behave reasonable with Degrees Celsius

When using a Quantity with the unit of "DegreesCelsius" multiplication doesn't work as expected. If you have 10 degrees and ...