[R] help with nls fitting

2011-08-20 Thread Paola Lecca
Dear all,

I'm trying to fit the following function

slope_pp3_mrna = ( (k3 * v3_K_d *p1^v3_h) / ( (v3_Kd^v3_h) + p2^v3_h ) ) *
   ( 1/(1 + (p2/v4_Kd)^v4_h) )  - pp3_mrna


to this experimental data in the datafraeme Data_pp3_mrna (see it at the
end of this e-mail)

I'm using the nls function in the following code. IN the last step of the
fit fm_pp3_mrna_4, when I add to the funziont the paramter v4_Kd something
goes wrong, and I reeive this message


Error in numericDeriv(form[[3L]], names(ind), env) :
  Missing value or an infinity produced when evaluating the model
What could be the error? I tried with differnet intial values of v4_Kd, but
I did not fix the problem.

Here below the code. Thanks in advance,
Paola.

Data_pp3_mrna - data.frame(
p1 = protein_1,
p2 = protein_2,
pp3_mrna = protein_3_mrna,
slope_pp3_mrna = stinemanSlopes(times,
protein_3_mrna)
)

one_par - nls(slope_pp3_mrna ~ ( (k3 * p1) / ( (1) + p1 ) ) *
( 1/(1 + (p2)) )  - pp3_mrna,
data=Data_pp3_mrna,
start=list(
   k3=0.1
  ))
summary(one_par)

fm_pp3_mrna_1 - nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1) / ( (v3_Kd) + p1 ) )
*
   ( 1/(1 + (p2)) )  - pp3_mrna,
data=Data_pp3_mrna,
start=list(k3=24,
   v3_Kd=1
   ))
summary(fm_pp3_mrna_1)

fm_pp3_mrna_2 - nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1^v3_h) / (
(v3_Kd)^v3_h + p1^v3_h ) ) *
   ( 1/(1 + (p2)) )  - pp3_mrna,
control = list(maxiter = 500),
data=Data_pp3_mrna,
start=list(k3=69,
   v3_Kd=0.3238,
   v3_h=1
   ))
summary(fm_pp3_mrna_2)

fm_pp3_mrna_3 - nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1^v3_h) / (
(v3_Kd)^v3_h + p1^v3_h ) ) *
   ( 1/(1 + (p2)^v4_h) )  - pp3_mrna,
control = list(maxiter = 500),
data=Data_pp3_mrna,
start=list(k3=37.451,
   v3_Kd=0.59,
   v3_h=2.013,
   v4_h=0.01
   ))

summary(fm_pp3_mrna_3)

fm_pp3_mrna_4 - nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1^v3_h) / (
(v3_Kd)^v3_h + p1^v3_h ) ) *
   ( 1/(1 + (p2/v4_Kd)^v4_h) )  - pp3_mrna,
control = list(maxiter = 500),
data=Data_pp3_mrna,
start=list(k3=56.2823,
   v3_Kd=0.3366,
   v3_h=1.8040,
   v4_Kd=0.03,
   v4_h=0.7693
   ))

Here the data.


 Data_pp3_mrna
   p1 p2  pp3_mrna slope_pp3_mrna
1   1.006  0.921 0.041 8.63741887
2   2.235  2.047 2.9069031 2.82619343
3   3.744  3.937 4.052 0.84354113
4   4.222  9.340 4.3237353 0.47577213
5   9.022 14.609 4.531-0.03940131
6  11.326 22.765 3.510-2.0420
7   6.899 17.852 2.489-1.86822481
8  10.709 27.777 1.6222048-1.55625973
9  14.084 27.785 0.911-0.48800514
10 14.922 23.613 0.826-0.1700
11 14.340 18.422 0.741-0.22560156
12 13.066 24.085 0.599-0.2840
13 17.553 18.594 0.457-0.13847372
14 14.803 16.831 0.4550965 0.03588624
15 11.945 14.495 0.493 0.09536674
16 11.427 12.458 0.5505361 0.15549062
17 11.556  9.082 0.649 0.49638596
18 20.107  9.987 1.2486525 1.36871828
19 15.999 10.305 2.059 1.87868197
20 16.094  5.793 3.2285000 2.3390
21 11.752  6.944 4.398 0.80395869
22 15.841  5.575 4.651 0.5060
23 12.601  5.221 4.904 0.80270128
24 13.598  2.872 5.819 1.8300
25 13.879  2.883 6.734-0.03571884
26 16.270  2.213 6.4135000-0.6410
27 17.176  3.381 6.093-0.33913760
28 12.332  2.781 6.032-0.1220
29 12.373  3.073 5.971-0.41224459
30 14.781  2.948 5.489-0.9640
31 17.578  3.953 5.007-0.68258311
32 18.865  2.279 4.7568901-0.39425557
33 14.735  2.806 4.606 0.13264481
34 16.160  1.676 4.987 0.7620
35 13.416  2.478 5.368 0.63914248
36 13.864  1.394 5.6374239 0.45419096
37 16.219  2.299 5.827-0.12540453
38 13.249  1.457 5.2505000-1.1530
39 14.445  2.325 4.674-0.09880849
40 13.210  2.230 5.5576966 2.17200142
41 12.358  2.116 8.94711.38521228


-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*

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and provide commented, minimal, self-contained, reproducible code.


[R] fit a 2-variables function to data

2011-08-05 Thread Paola Lecca
Dearl all,

I have to fit a function

y = f(x1, x2)
to data experiemntal data describing the measured behavior of y.

x1 and x2 are the independent variables.

Could you suggest me wich R package can I use for this purpose?

Thanks,
Paola.


-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*

[[alternative HTML version deleted]]

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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


[R] problemsn in using nls

2011-08-05 Thread Paola Lecca
Dear all,

I tried to use nls, but I got the following error

Error in numericDeriv(form[[3L]], names(ind), env) :
  Missing value or an infinity produced when evaluating the model

Any suggestion?



Thanks,

Paola.



The code I wrote is



Data_pp2_mrna - data.frame(
p1 = protein_1,
p6 = protein_6,
pp2_mrna = protein_2_mrna,
slope_pp2_mrna = stinemanSlopes(times,
protein_2_mrna)
)


fm_pp2_mrna - nls(slope_pp2_mrna ~ ( (k1 * v2_Kd *p1^v2_h) / ( (v2_Kd^v2_h)
+ p1^v2_h ) ) * ( 1/(1 + (p6/v5_Kd)^v5_h) ) - pp2_mrna,
 data = Data_pp2_mrna,
 start = list(k1 = 1,
  v2_Kd = 1,
  v2_h = 1,
  v5_Kd = 1,
  v5_h = 1
  ))


The data are as follows



 Data_pp2_mrna
   p1 p6  pp2_mrna slope_pp2_mrna
1   1.006  1.234 0.000   1.0183976996
2   2.235  0.693 0.5565718   1.2167043185
3   3.744  0.451 1.230   1.6962541888
4   4.222  0.441 2.620   2.78
5   9.022  0.523 4.010   0.1298238635
6  11.326  0.845 3.9179535  -0.2048280861
7   6.899  0.674 3.805  -0.4595669210
8  10.709  1.369 3.386  -0.838000
9  14.084  1.646 2.967  -0.5032137310
10 14.922  2.561 2.822  -0.29
11 14.340  2.265 2.677  -0.300152
12 13.066  4.832 2.4634792  -0.4859794757
13 17.553  5.651 2.188  -0.7700435122
14 14.803  6.418 1.6045000  -1.167000
15 11.945 10.343 1.021  -0.3160241819
16 11.427  9.415 1.0435000   0.045000
17 11.556 12.610 1.066  -0.1700195282
18 20.107 16.171 0.8545000  -0.423000
19 15.999 13.189 0.643  -0.1721421868
20 16.094 17.022 0.6635000   0.041000
21 11.752 14.723 0.684  -0.0911220974
22 15.841 15.887 0.569  -0.23
23 12.601 15.604 0.454  -0.0022539547
24 13.598 18.202 0.5665000   0.225000
25 13.879 20.821 0.679  -0.0155566571
26 16.270 18.040 0.549  -0.26
27 17.176 16.015 0.419  -0.1195632728
28 12.332 18.429 0.425   0.012000
29 12.373 17.723 0.431  -0.1118527520
30 14.781 23.100 0.3095000  -0.243000
31 17.578 15.396 0.188   0.0004440266
32 18.865 21.408 0.310   0.244000
33 14.735 14.518 0.432   0.0473462057
34 16.160 21.351 0.361  -0.142000
35 13.416 16.689 0.290   0.0424156026
36 13.864 17.015 0.4065000   0.233000
37 16.219 21.776 0.523   0.1567965535
38 13.249 17.371 0.5650035   0.0498847737
39 14.445 19.218 0.573  -0.0435396634
40 13.210 21.309 0.5211514  -0.1713939796
41 12.358 24.966 0.400  -0.3132118164

-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*

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and provide commented, minimal, self-contained, reproducible code.


[R] use of modMCMC

2011-08-04 Thread Paola Lecca
Dear all,

I used modFit of the package FME to fit a set of ODE to a ste of eperiemntal
data.

The summary of this fit give me the following error

 summary(Fit)

Residual standard error: 984.1 on 452 degrees of freedom
Error in cov2cor(x$cov.unscaled) : 'V' is not a square numeric matrix
In addition: Warning message:
In summary.modFit(Fit) : Cannot estimate covariance; system is singular

This is due becasue the Hessian matrix has all the entries equal to 0.

In these cases, on the help page of modFit, it is suggested to use modMCMC
to generate new sets of parameters. modMCMC performs a Markov Chain Monte
Carlo simulation.

I do not understand very well how modMCMC can be used in a context of
parameter estimation. Could someone help me in understanding the use of this
function and its utility for parameter fiting?

Thank you very much in advance,
Paola.
-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*

[[alternative HTML version deleted]]

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R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


[R] use of modMCMC

2011-08-04 Thread Paola Lecca
Dear all,



I used modFit of the package FME to fit a set of ODE to a ste of
experimental data.

The summary of this fit give me the following error

 summary(Fit)
Residual standard error: 984.1 on 452 degrees of freedom
Error in cov2cor(x$cov.unscaled) : 'V' is not a square numeric matrix
In addition: Warning message:
In summary.modFit(Fit) : Cannot estimate covariance; system is singular


This is due becasue the Hessian matrix has all the entries equal to 0 in my
system.

In these cases, on the help page of modFit, it is suggested to use modMCMC
to generate new sets of parameters. modMCMC performs a Markov Chain Monte
Carlo simulation.

I do not understand very well how modMCMC can be used in a context of
parameter estimation. Could someone help me in understanding the use of this
function and its utility for parameter fitting?



Thank you very much in advance,

Paola.
-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*

[[alternative HTML version deleted]]

__
R-help@r-project.org mailing list
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and provide commented, minimal, self-contained, reproducible code.


[R] Help with modFit of FME package

2011-08-01 Thread Paola Lecca
Dear R users,

I'm trying to fit a set an ODE to an experimental time series. In the
attachment you find the R code I wrote using modFit and modCost of FME
package and the file of the time series.

When I run summary(Fit) I obtain this error message, and the values of the
parameters are equal to the initial guesses I gave  to them.

The problem is not due to the fact that I have only one equation (I tried
also with more equations, but I still obtain this error).

I would appreciate if someone could help me in understanding the reason of
the error and in fixing it.

Thanks for your attention,
Paola Lecca.

Here the error:

 summary(Fit)

Parameters:
 Estimate Std. Error t value Pr(|t|)
pro1_strength1 NA  NA   NA

Residual standard error: 2.124 on 10 degrees of freedom
Error in cov2cor(x$cov.unscaled) : 'V' is not a square numeric matrix
In addition: Warning message:
In summary.modFit(Fit) : Cannot estimate covariance; system is singular




__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.




-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*
timepp1_mrna
0   0
2   2.754
4   2.958
6   4.058
8   3.41
10  3.459
12  2.453
14  1.234
16  2.385
18  3.691
20  3.252
__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


[R] Help with modFit of FME package 2

2011-08-01 Thread Paola Lecca
* Apologies for multiple posting *
I attached to my previous e-mail a .r file, and it was not permitted by the
rules of the mailing lis. Again, please receive my sincere apologies for
this.

I re-send again the e-mail with .txt attachemnt in the hope someone an help
me to solve my problem.


I'm trying to fit a set an ODE to an experimental time series. In the
attachment you find the R code I wrote using modFit and modCost of FME
package and the file of the time series.

When I run summary(Fit) I obtain this error message, and the values of the
parameters are equal to the initial guesses I gave  to them.

The problem is not due to the fact that I have only one equation (I tried
also with more equations, but I still obtain this error).

I would appreciate if someone could help me in understanding the reason of
the error and in fixing it.

Thanks for your attention,
Paola Lecca.

Here the error:

 summary(Fit)

Parameters:
 Estimate Std. Error t value Pr(|t|)
pro1_strength1 NA  NA   NA

Residual standard error: 2.124 on 10 degrees of freedom
Error in cov2cor(x$cov.unscaled) : 'V' is not a square numeric matrix
In addition: Warning message:
In summary.modFit(Fit) : Cannot estimate covariance; system is singular




__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.




-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*
timepp1_mrna
0   0
2   2.754
4   2.958
6   4.058
8   3.41
10  3.459
12  2.453
14  1.234
16  2.385
18  3.691
20  3.252
require(deSolve)
require(FME)


##
#  PART 1   
 #
##

# Differential equations
model_1_part_1 - function(t, S, parameters)
 {
  with(as.list(parameters), {
  #
  cod1 = pro1_strength
  #
  pp1_mrna_degradation_rate - 1
  
###
  #
  v1 = cod1
  v2 = pp1_mrna_degradation_rate * S[1]
  #
  
#
  #
  dS1 = v1 - v2
  #
  

  #
  list(c(dS1))
 })
}


# Parameters
parms_part_1 - c(pro1_strength = 1.0)

# Initial values of the species concentration
S - c(pp1_mrna = 0)

times - seq(0, 20, by = 2)

# Solve the system
ode_solutions_part_1 - ode(S, times, model_1_part_1, parms = parms_part_1)
ode_solutions_part_1

summary(ode_solutions_part_1)

## Default plot method
plot(ode_solutions_part_1)





# Estimate of the parameters
experiment - read.table(./wild_pp1_mrna.txt, header=TRUE)

rw - dim(experiment)[1]

names - array(, rw)
for (i in 1:rw)
{
 names[i] - pp1_mrna
}
names
  
observed_data_part_1 - data.frame(name = names,
   time = experiment[,1], val = experiment[,2])

observed_data_part_1

ode_solutions_part_1

Cost_function - function (pars) {
 out - ode_solutions_part_1
 cost - modCost(model = out, obs = observed_data_part_1, y = val)
 cost
 }

Cost_function(parms)

# Fit the model to the observed data
Fit - modFit(f = Cost_function, p = parms_part_1)
Fit


# Summary of the fit
summary(Fit)

# Model coefficients
coef(Fit)

# Deviance of the fit
deviance(Fit)__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


[R] Help with modFit of FME package

2011-07-28 Thread Paola Lecca
Dear R users,



I’m trying to fit a set an ODE to an experimental time series. In the
attachment you find the R code I wrote using modFit and modCost of FME
package and the file of the time series.



When I run summary(Fit) I obtain this error message, and the values of the
parameters are equal to the initial guesses I gave  to them.



The problem is not due to the fact that I have only one equation (I tried
also with more equations, but I still obtain this error).



I would appreciate if someone could help me in understanding the reason of
the error and in fixing it.



Thanks for your attention,

Paola.



Here the error:



 summary(Fit)



Parameters:

  Estimate Std. Error t value Pr(|t|)

pro1_strength1 NA  NA   NA



Residual standard error: 2.124 on 10 degrees of freedom

Error in cov2cor(x$cov.unscaled) : 'V' is not a square numeric matrix

In addition: Warning message:

In summary.modFit(Fit) : Cannot estimate covariance; system is singular




-- 
*Paola Lecca, PhD*
*The Microsoft Research - University of Trento*
*Centre for Computational and Systems Biology*
*Piazza Manci 17 38123 Povo/Trento, Italy*
*Phome: +39 0461282843*
*Fax: +39 0461282814*
timepp1_mrna
0   0
2   2.754
4   2.958
6   4.058
8   3.41
10  3.459
12  2.453
14  1.234
16  2.385
18  3.691
20  3.252
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


[R] Help with modFit of FME package

2011-07-28 Thread Paola Lecca
Dear R users,

I'm trying to fit a set an ODE to an experimental time series. In the 
attachment you find the R code I wrote using modFit and modCost of FME package 
and the file of the time series.

When I run summary(Fit) I obtain this error message, and the values of the 
parameters are equal to the initial guesses I gave  to them.

The problem is not due to the fact that I have only one equation (I tried also 
with more equations, but I still obtain this error).

I would appreciate if someone could help me in understanding the reason of the 
error and in fixing it.

Thanks for your attention,
Paola Lecca.

Here the error:

 summary(Fit)

Parameters:
  Estimate Std. Error t value Pr(|t|)
pro1_strength1 NA  NA   NA

Residual standard error: 2.124 on 10 degrees of freedom
Error in cov2cor(x$cov.unscaled) : 'V' is not a square numeric matrix
In addition: Warning message:
In summary.modFit(Fit) : Cannot estimate covariance; system is singular



timepp1_mrna
0   0
2   2.754
4   2.958
6   4.058
8   3.41
10  3.459
12  2.453
14  1.234
16  2.385
18  3.691
20  3.252
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.