[BioC] plotpfm has been removed in PWMEnrich?
Fabrice Tourre
fabrice.ciup at gmail.com
Wed Dec 11 22:01:05 CET 2013
pm <- PFMtoPWM(pfm)
pm at pwm <- heights
plot(pm)
This plot is not good. Because we cannot control y-axis
On Wed, Dec 11, 2013 at 3:44 PM, Fabrice Tourre <fabrice.ciup at gmail.com> wrote:
> Dear Robert,
>
> Thank you. When I have the heights matrixs, how can we get a weblogo plot?
>
> On Wed, Dec 11, 2013 at 5:44 AM, Robert Stojnic <rainmansr at gmail.com> wrote:
>>
>> Hi Fabrice,
>>
>> The negative values are usual as the PWM matrix is defined as log2
>> probability_base / probability_background. So if the any of the
>> probabilities is smaller than 0.25 in your input matrix, this will give a
>> negative value. Maybe you wanted to get the heights of the individual
>> letters in the logo?
>>
>> # convert the count matrix to probabilities
>> p = t(t(pfm) / colSums(pfm))
>>
>> # this is without the small-sample correction, for more information see
>> https://en.wikipedia.org/wiki/Sequence_logo or the original paper
>> h = - colSums(p * log2(p))
>> heights = t(t(p) * (2-h))
>>
>> All the transpositions (calls to t()) are needed to make sure the matrix and
>> vector operations are carried out along the correct dimensions.
>>
>> Cheers, Robert
>>
>>
>> On 10/12/13 16:41, Fabrice Tourre wrote:
>>>
>>> PWM always give me some negative value. This strange to me.
>>>
>>> PFMtoPWM(pfm)
>>> An object of class 'PWM'
>>> ID:
>>> Target name:
>>> Frequency matrix:
>>> $pfm
>>> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
>>> A 3289112 3286601 3324808 3295086 3297953 3371158 3350851 3380593 3406893
>>> C 2770671 2771901 2749093 2791942 2791869 2756225 2779305 2780189 2727296
>>> G 2836085 2853221 2826205 2830413 2845211 2809652 2778112 2742323 2542202
>>> T 3286234 3270379 3281996 3264661 3247069 3245067 3273834 3278997 3505711
>>> [,10] [,11] [,12] [,13] [,14] [,15] [,16] [,17] [,18]
>>> A 3293358 2178674 4352405 3227324 3461232 3446487 3259436 3276060 3271729
>>> C 2663331 2932504 2139363 3052255 2674074 2550187 3005584 2805702 2844711
>>> G 2467603 2413635 1644787 2028507 2906055 2827872 2948758 3050624 2971989
>>> T 3757810 4657289 4045547 3874016 3140741 3357556 2968324 3049716 3093673
>>> [,19] [,20] [,21]
>>> A 3297076 3293868 3334010
>>> C 2853311 2824444 2768038
>>> G 2891960 3017416 2974502
>>> T 3139755 3046374 3105552
>>> Position weight matrix (PWM):
>>> $pwm
>>> [,1] [,2] [,3] [,4] [,5] [,6]
>>> A 0.1110069 0.10990513 0.1265798 0.1136249 0.11487965 0.14655305
>>> C -0.1364558 -0.13581544 -0.1477355 -0.1254222 -0.12545992 -0.14399751
>>> G -0.1027904 -0.09409968 -0.1078251 -0.1056786 -0.09815553 -0.11629972
>>> T 0.1097440 0.10276665 0.1078823 0.1002420 0.09244685 0.09155707
>>> [,7] [,8] [,9] [,10] [,11] [,12]
>>> A 0.1378363 0.1505851 0.1617654 0.1128682 -0.4832408 0.5151216
>>> C -0.1319670 -0.1315082 -0.1592199 -0.1934594 -0.0545581 -0.5095098
>>> G -0.1325864 -0.1512927 -0.2606125 -0.3035809 -0.3354836 -0.8887903
>>> T 0.1042900 0.1065634 0.2030159 0.3032009 0.6127992 0.4096436
>>> [,13] [,14] [,15] [,16] [,17]
>>> [,18]
>>> A 0.083647231 0.18459445 0.1784354 0.09793116 0.105270587 0.10336206
>>> C 0.003184313 -0.18765178 -0.2560881 -0.01904584 -0.118329389 -0.09840908
>>> G -0.586272844 -0.06762917 -0.1069744 -0.04658375 0.002413189 -0.03526240
>>> T 0.347138703 0.04441379 0.1407203 -0.03704261 0.001983716 0.02262953
>>> [,19] [,20] [,21]
>>> A 0.11449595 0.1130915480 0.13056724
>>> C -0.09405417 -0.1087242780 -0.13782742
>>> G -0.07464358 -0.0133775737 -0.03404303
>>> T 0.04396080 0.0004018867 0.02815854
>>> With background nucleotide frequencies which also serve as pseudo-count:
>>> $prior.params
>>> A C G T
>>> 0.25 0.25 0.25 0.25
>>>
>>> On Tue, Dec 10, 2013 at 7:29 AM, Robert Stojnic <rainmansr at gmail.com>
>>> wrote:
>>>>
>>>> Dear Fabrice,
>>>>
>>>> You can plot the PFM in PWMEnrich by converting it to PWM:
>>>>
>>>> plot(PFMtoPWM(pfm_matrix))
>>>>
>>>> Unfortunately the old function was deprecated. Sorry if it broke your
>>>> code!
>>>>
>>>> Cheers, Robert
>>>>
>>>>
>>>> On 07/12/13 04:41, Fabrice Tourre wrote:
>>>>>
>>>>> Dear expert,
>>>>>
>>>>> I just want to plot PFM using PWMEnrich package. It seems seqlogo
>>>>> cannot do this. But I found in PWMEnrich2.6.2, plotpfm does not exist.
>>>>> How can I plotPFM using new PWMEnrich?
>>>>>
>>>>> _______________________________________________
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>>>>>
>>
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