Questions tagged [units]

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

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8 views

Issue displaying units with Quantity[] inside bar legend

Quantity[] is displaying some inconsistent behaviour when used in BarLegend[]. Compare the following two examples: ...
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1answer
42 views

Issues arising when using UnitSimplify for getting a dimensionless expression

I am having some difficulties when using UnitSimplify in manipulating expressions for obtaining dimensionless quantities in Mathematica 12.0.0. Here is a minimal ...
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27 views

Plotting a quantity-based function doesn't work

Creating the function: ...
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32 views

How to deal with units while plot?

I am plotting a bistable plot and the given code is giving me the bistable plot. But there is one problem in the plot. In the x-axis "P0" is multiplied with 10^(3) p. second. and in the y-axis, the ...
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68 views

Comparison of tagged units

Consider this data set: BNikkei = {{10.0032, 27 Days}, {10.0527, 22 Days}, {10.1283, 18 Days}} from a recent question, "More effective way to apply a function ...
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Force Solve to respect unit system

I give Solve quantities in FPS and it returns resulting quantities in SI, necessitating that I add an entire section to my workflow where I pick apart the solution ...
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63 views

UnitConvert having trouble multiplying Boltzmann's Constant with Fahrenheit?

T:=70 Quantity["DegreesFahrenheit"] kb:=Quantity["BoltzmannConstant"] UnitConvert[kb UnitConvert[T, "Kelvins"], "Electronvolts"] // N Returns 0.0253575 eV while <...
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77 views

Why aren't radians dimensionless?

α = Quantity[-3, ("Radians")/("Seconds")^2]; ω = Quantity[-4, ("Radians")/("Seconds")]; r = Quantity[2, "Feet"]; at = α r an = ω^2 r a = Sqrt[an^2 + at^2] ...
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30 views

Computing matrix eigenvalues with units

I apologize if this is a basic question or if I am not giving enough detail. I'm trying to solve for the eigenvalues of a matrix with matrix elements that have units. ...
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1answer
49 views

Using physics constant in calculation

I know that mathematica knows physical constants https://reference.wolfram.com/language/guide/Units.html If I write down = PlanckConstant it "recognizes" hbar. My question is: how can I use in an ...
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21 views

What is the reason StandardDeviation doesn't cooperate with Quantity “Percent”?

Consider the following list of numbers y = {13, 0.2, 11.201}; Turning y into a list of ...
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0answers
38 views

How to handle Units when Integrating?

I have some functions defined, which are to use units. Now another function is used to integrate over those, with the integration variable also quantified and the input to said function. I better just ...
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57 views

Does AroundReplace work with Quantity?

When I try to use AroundReplace with units it issues Around::compat message and outputs something strange: ...
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55 views

UnitSimplify rules?

Code as following: ...
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1answer
32 views

GeoDistance and Excel export

I'm trying to export the distance matrix below to an excel file. I have no interested on the unit. I just care the value of a distance. A standard export command does not work properly. How should I ...
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37 views

Any progress on Plots of Quantities?

Plots of quantities still don't seem to work. I've implemented the one suggestion people have: use Evaluate, but now the values of my plots are just completely off ...
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1answer
79 views

How to plot $ \sin\theta $ in degree? [closed]

Please suggest how to plot $ \sin\theta $ in degree. I am trying using the given below code but it is not working (It works if used Ticks without ...
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1answer
103 views

How to add some bytes quantity?

I have some strings like: st={"29M", "53K", "27K", "5.0M", "29M", "4.0K", "4.0M", "114M", "20K", "1.3G"} They are some bytes quantity, could we add or sort them ...
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32 views

Mathematica not simplifying expressions with units

Hi I'm having an issue with the Quantity system. On the guide for units on the wolfram page, there is an example ...
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3answers
410 views

Why is Mathematica messing with the time units in this simple equation? [closed]

If you lets say work 40 hours every week and your working days total to 251/5 weeks for a particular year. Then why is Mathematica messing this calculation and producing incorrect result? ...
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44 views

Is there a way to include holiday calendar into Quantity system?

Suppose I have a long list of business hours but in different denominations for postings like as follows. If I just use the vanilla UnitConvert it just does a ...
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2answers
130 views

Getting useful units for combinations of physical constants like on WolframAlpha?

When I need to do order of magnitude estimates, I often encounter situations where I have a mess of physical constants and difficulty putting them in sensible units. For example, consider the ...
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2answers
54 views

Extract values from strings according to units

I have a lot of strings, which have simple nomenclature of number-unit associations and am looking to extract the number according to the units. For example: ...
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1answer
46 views

Force UnitConvert to display the proper unit prefix and return inexact quantities? [closed]

I'm experimenting with units: UnitConvert[1/Quantity[2.0, "GHz"]] 5.*10^-10s ...
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3answers
57 views

Changing Y-Axis to “Billions of Dollars”

Is there a way to change my bar chart's Y-axis from powers of 10 to "billions of dollars"? For example $100,000,000,000 should read as ...
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2answers
77 views

Unitless quantities

There are many cases in science where a quantity should end up unitless. Yet the units capabilities of Mathematica seem to have a problem with such situations. For example: ...
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0answers
37 views

What is used for the % symbol in mathematica? [duplicate]

Im new in mathematica i want to know logic about this program. I got this code: {{vo, vn, Ii}} = {vo, vn, Ii} /. %; i know that the syntax /. is for replacement but i dont know whats going on with ...
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2answers
1k views

How to get Planck length in meters to 6 decimal places

I want Mathematica to format quantities to more decimal places than the default. For example I have tried ...
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0answers
46 views

Manipulating a ParametricFunction to handle units

I have a pretty nice way to handle units on a result from NDSolve, which basically consists of converting all of the units to SI, stripping them, calling NDSolve, and then putting the units back. I'll ...
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1answer
39 views

TargetUnits aren't working as expected on an InterpolatingFunction

Short version: My understanding of the use of TargetUnits in a Plot statement is that if the function being plotted has units, MMA will attempt to convert the output of that function to the unit form ...
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1answer
152 views

Very slow rendering of Quantity

I noticed since Mathematica v12 a very slow frontend when rendering the Units. Easy to show: Quantity[Range[1, 100], "Euros"] Takes (timed with a stopwatch) ...
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29 views

SemanticImport changes “string” type to “quantity” type--how to change during import or after import?

This question may overlap with other questions about the quirks of SemanticImport, but I don't see this specific wrinkle on StackExchange and I hope it will be a simple answer to help me and others ...
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28 views

Problem with UnitConvert with a list

I'm studying this part of the course units convert I have two list the first: is in Megaparsec and I need to transform it to kilometers ...
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1answer
108 views

How can I add units to variables inside Manipulate?

I've created a Manipulate expression with many variables. I would like each of these variables to have associated units as in the standard Quantity[Value,"Unit"] so that I can easily enter the values ...
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1answer
126 views

NDSolve and Quantity[]

I'm working on a set of relatively basic ODEs of a physical pendulum and motor: $$\left\{\text{jb} \theta ''(t\text{s})+\text{rb} \theta '(t\text{s})+\alpha \sin (\theta (t\text{s}))+\mu \tan ^{-1}\...
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1answer
98 views

Scientific Notation for Quantities

I am using Quantities (units) in Mathematica 11.3 and would like to express the numerical portion of the output in scientific notation. The command ...
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1answer
675 views

Mathematica seems confused about Kilograms vs KilogramsForce

This does what I expect: Quantity["Kilograms"*"Meters"] // InputForm Quantity[1, "Kilograms"*"Meters"] This, on the other hand, bungles the units: ...
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3answers
200 views

Specify set of base units to use in UnitConvert

I am trying to convert arbitrary units to CGS. I know this can get a bit tricky with ESU, but for this question that does not need to be addressed. What I would like to do is to give a quantity-to-...
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1answer
56 views

How to change all stock prices to USD?

I want to create DateListPlot that compares prices of cellphone manufacturers' stocks over the last 13 years. Stocks include Nokia, Blackberry, Samsung, LG, Motorola, and Sony-Ericsson. The problem is ...
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2answers
193 views

Why does using different units but same physical value give different result?

I'm trying to define a variable with the value of the thermal constant $V_T$. The value of the thermal constant is given in Volts as $V_T = \frac{k T}{q}$, where $k$ is the Boltzmann constant and $q$ ...
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1answer
68 views

Bizarre Problem with Wolfram Knowledgebase: Extracting Values

[System: Mas OS Mojave; Version: 11.3.0.0] I tried to use the knowledgebase, because why not, but got a strange result: I also tried another lookup for good measure: Plaintext code: EntityValue[{...
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1answer
74 views

Custom conversion rules in UnitConvert

I want to make UnitConvert operate on custom units with special rules. For instance, I would like to be able to convert between ...
2
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1answer
64 views

Convert time interval to mixed units without leading zeros

Let's say I have time intervals in seconds. I am looking for a method that produces the following conversions: 3660 => ...
4
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1answer
126 views

Problem using UnitConvert

As we know in physics, power = torque * (angular velocity). But when I use UnitConvert to convert a quantity expressing power/(angular velocity) into newton-meters, ...
2
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1answer
354 views

Convert decibels to amplitude - Built-in function

Is there a built-in function to convert decibels to amplitude in Mathematica? I tried with: UnitConvert[Quantity[40, "decibels"], "amplitude"] but it does not ...
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0answers
74 views

Join on QuantityArray

I need to merge two QuantityArray objects of mixed type. My first attempt looks something like: ...
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3answers
130 views

Multiplying quantities by scalars in Mathematica 11.3

I'm no longer able to multiply scalars by quantities in Mathematica 11.3. In previous versions the code 3*Quantity[1, "mm"] evaluated to ...
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1answer
76 views

FinancialData returns undefined Units for Volume or randomly fails

Recently FinancialData["IBM","Volume"] started failing and when it does randomly work, it returns Quantity[3073167,Shares] but ...
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51 views

Interpreter for Quantities without magnitude

When using a quantity interpreter on a unit without magnitude, the interpreter fails, but works fine on quantities with magnitudes. Ex: ...
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1answer
79 views

Meter newtons revolutions / second is not compatible with Watts

When I do ...

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