MathGroup Archive 2004

[Date Index] [Thread Index] [Author Index]

Search the Archive

RE : Maen

  • To: mathgroup at smc.vnet.net
  • Subject: [mg48136] RE : [mg48119] Maen
  • From: "Florian Jaccard" <florian.jaccard at eiaj.ch>
  • Date: Fri, 14 May 2004 20:58:51 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Hello !

It works fine on my computer ! 
But you can use the   << "Statistics`DescriptiveStatistics`"  package... It
worked in previous versions...

In[1]:=
boys = 
  {192, 176, 178, 180, 189, 173, 177, 176, 176, 194,
    178, 172, 175, 180, 170, 174, 180, 184, 177, 181,
    190, 186, 187, 184, 190, 180, 178, 182, 181, 180,
    175, 182, 182, 181, 179, 190, 173, 189, 173, 183,
    172, 178, 182, 172, 190, 180, 176, 177, 181, 185,
    174, 178, 178, 178, 170, 175, 178, 186, 185, 182,
    179, 187, 183, 188, 191, 180, 193, 183, 185, 174,
    174, 180, 191, 180, 177, 185, 192, 187, 170, 176,
    170, 184, 179, 173, 184, 184, 190, 179};


In[2]:=
Mean[boys]//N

Out[2]=
180.705

And, if you want to look at other possibilities, use the packages
DataManipulation and DescriptiveStatistics.

For example, try the following inputs :

In[45]:=
<< "Statistics`DataManipulation`"

In[46]:=
effectifs = BinCounts[boys, {157.5, 207.5, 5}]

In[47]:=
BinLists[boys, {157.5, 207.5, 5}]; 

In[48]:=
centres = Table[i, {i, 160, 205, 5}]

In[49]:=
<< "Graphics`Graphics`"

In[50]:=
BarChart[Transpose[{effectifs, centres}], 
   AxesLabel -> {"height", "number of boys"}]; 

In[51]:=
BarChart[Transpose[{effectifs*(100/Plus @@ effectifs), 
     centres}], AxesLabel -> {"height", "%"}]; 

In[52]:=
effectifsCumulés = Table[Plus @@ Take[effectifs, i], 
   {i, 1, Length[effectifs]}]

In[53]:=
BarChart[Transpose[{effectifsCumulés, centres}], 
   AxesLabel -> {"height", 
     "number of boys with heigth at least..."}]; 

In[54]:=
<< "Statistics`DescriptiveStatistics`"

Mean :

In[55]:=
N[Mean[boys]]

Median :

In[56]:=
Median[boys]

Mode :

In[57]:=
Mode[boys]

Variances :

In[58]:=
N[VarianceMLE[boys]]

Or, using division by n-1 :

In[59]:=
N[Variance[boys]]

StandardDeviations :

In[60]:=
N[StandardDeviationMLE[boys]]

Using division by n-1 :

In[61]:=
N[StandardDeviation[boys]]


Greetings

F.Jaccard


-----Message d'origine-----
De : per.ronne at doesnt.work.spam.filter.invalid
[mailto:per.ronne at doesnt.work.spam.filter.invalid] 
Envoyé : vendredi, 14. mai 2004 06:14
À : mathgroup at smc.vnet.net
Objet : [mg48119] Maen

I've just purchased Mathematica 5 but I've got some problems.

I write:

boys = 
  {192, 176, 178, 180, 189, 173, 177, 176, 176, 194,
    178, 172, 175, 180, 170, 174, 180, 184, 177, 181,
    190, 186, 187, 184, 190, 180, 178, 182, 181, 180,
    175, 182, 182, 181, 179, 190, 173, 189, 173, 183,
    172, 178, 182, 172, 190, 180, 176, 177, 181, 185,
    174, 178, 178, 178, 170, 175, 178, 186, 185, 182,
    179, 187, 183, 188, 191, 180, 193, 183, 185, 174,
    174, 180, 191, 180, 177, 185, 192, 187, 170, 176,
    170, 184, 179, 173, 184, 184, 190, 179}

But when I try to get their average height [it is the height of boys in
Danish upper grammar schools, grade 13 at the age of around 19], I get:

Mean[boys]
Mean[{192, 176, 178, 180, 189, 173, 177, 176, 176, 194, 178, 172, 175,
180, 
    170, 174, 180, 184, 177, 181, 190, 186, 187, 184, 190, 180, 178,
182, 181,
     180, 175, 182, 182, 181, 179, 190, 173, 189, 173, 183, 172, 178,
182, 
    172, 190, 180, 176, 177, 181, 185, 174, 178, 178, 178, 170, 175,
178, 186,
     185, 182, 179, 187, 183, 188, 191, 180, 193, 183, 185, 174, 174,
180, 
    191, 180, 177, 185, 192, 187, 170, 176, 170, 184, 179, 173, 184,
184, 190,
     179}]

And it doesn't help to put on a //N:

Mean[boys] // N
Mean[{192., 176., 178., 180., 189., 173., 177., 176., 176., 194., 178.,
172., 
    175., 180., 170., 174., 180., 184., 177., 181., 190., 186., 187.,
184., 
    190., 180., 178., 182., 181., 180., 175., 182., 182., 181., 179.,
190., 
    173., 189., 173., 183., 172., 178., 182., 172., 190., 180., 176.,
177., 
    181., 185., 174., 178., 178., 178., 170., 175., 178., 186., 185.,
182., 
    179., 187., 183., 188., 191., 180., 193., 183., 185., 174., 174.,
180., 
    191., 180., 177., 185., 192., 187., 170., 176., 170., 184., 179.,
173., 
    184., 184., 190., 179.}]

If I look up in the Stephen Wolfram's Mathematica book 5th Edition on
page 109, it should be possible to get:

data = {4.7, 7.2, 8.4, 5.8, 9.2, 3.9}
Mean[data]
6.46667

But instead I get:

Mean[{4.7, 7.2, 8.4, 5.8, 9.2, 3.9}]

What is wrong?
-- 
Per Erik Rønne




  • Prev by Date: RE: RE: Re: Mandelbrot Set & Mathematica
  • Next by Date: mechanical sound amplifications using a Limacon
  • Previous by thread: Re: Mean
  • Next by thread: mechanical sound amplifications using a Limacon