Hi michael, thanks, but here is more explanations of my questions to have more help, (also pls have a look at the data below):
 
Three questions to give more concrete help:

i) Is your data set stored as a matrix or a data.frame
My data is in a data frame
ii) What are you trying to get the mean of -- all variables pooled or of each variable independently? 
Actually I would like to have all the data for either u, v w1 or w2 that are bigger than75, which then there we’ll have new data frame with either u,v, w1 or w2 bigger than 75, doesn’t matter x,y,z1 and z2, they will just follow what ever the results would be (in this new data frame we should still have x,y,z1,z1,u, v,w1 and w2, but only those with the values of u or v or w1 or w2 that are bigger than 75.

iii) When you say >=75 for all variables, do you mean only use a row
if it's >=75 for each element or just only use the >=75 elements for
each calculation independently.


after we have the new data frame, then I would like to have the mean for x, y, z1 and z2 (the absolute number, without taking consideration the negative signs). If possible, Itshould have all the results altogether (mean of x=.., y=… z1=.. and z2= …)and not one by one.
 
Another question, if I would like to create a new data frame with only the maximum data of x (for example if I have 0.456; -0.456; and many more of this values as the maximum values of x ,How can I do it ? (withput taking consideration of the negative signs)
 I hope my questions are clear now.
Thanks in advance,
Yakamu 
Michael

 





x

y

Z1

Z2

u

v

W1

W2


-0.0077

-0.4665

-0.0048

-0.1302

70

26

59

54


-0.0028

-0.0055

0.0026

-0.001

62

42

82

62


-0.0123

0.006

-0.003

0.0029

74

18

83

78


0.0232

0.0367

0.0028

0.0027

65

34

74

78


-0.0075

0.1141

-0.0018

0.0363

63

0

77

69


0.004

-0.0032

0.0036

-0.0156

14

40

70

64


-0.003

-0.0392

-0.006

-0.0212

55

42

63

69


-0.0116

-0.0028

0.0031

0.0209

59

23

69

35


0.0171

-0.0496

-0.0055

0.0118

35

57

73

42


-0.0135

-0.0324

0.0001

0.0004

55

45

57

55


0.0345

0.004

0.0041

0.0079

77

38

57

71


-0.0206

-0.0152

0.003

0.0104

55

30

56

81


-0.0044

0.0343

0.0059

0.0105

74

52

58

75


0.0138

-0.065

0.0016

-0.0064

68

64

70

56


-0.0303

0.0012

-0.009

0.0025

66

32

42

52


-0.0231

0.0379

-0.0006

0.0116

70

49

61

34


0.0305

0.078

-0.0081

-0.0082

83

45

22

18


-0.03

0.0978

0.0118

0.0103

88

25

31

68


0.0072

-0.0019

0.0049

0.0055

79

50

67

71

--- On Wed, 2/1/12, R. Michael Weylandt <michael.weylandt@gmail.com> wrote:


From: R. Michael Weylandt <michael.weylandt@gmail.com>
Subject: Re: [R] how can i calculate the mean of my data which is only bigger than 75?
To: "Yakamu Yakamu" <iam_yakamu@yahoo.com>
Cc: "r-help@r-project.org" <r-help@r-project.org>
Date: Wednesday, February 1, 2012, 12:47 PM


I'm not entirely sure what you mean, but it's likely one of these:

apply(data, 2, function(x) mean(x[x>75]))
mean(data[ apply(data,1, function(x) all(x > 75), ])
mean(data[data>75])

Three questions to give more concrete help:

i) Is your data set stored as a matrix or a data.frame
ii) What are you trying to get the mean of -- all variables pooled or
of each variable independently?
iii) When you say >=75 for all variables, do you mean only use a row
if it's >=75 for each element or just only use the >=75 elements for
each calculation independently.

Michael


	[[alternative HTML version deleted]]

