# MultivariateStats.transform ,MethodError:

**URL:** https://discourse.julialang.org/t/multivariatestats-transform-methoderror/82825
**Category:** Data
**Tags:** data
**Created:** [June 15, 2022, 5:01pm UTC](https://discourse.julialang.org/t/multivariatestats-transform-methoderror/82825 "2022-06-15T17:01:35Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![raman\_kumar](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/raman_kumar/32/26782_2.png) [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)
#### Post date: [June 15, 2022, 5:01pm UTC](https://discourse.julialang.org/t/multivariatestats-transform-methoderror/82825/1 "2022-06-15T17:01:35Z")

</div>

How to overcome that Method error ?

 ![image](https://global.discourse-cdn.com/julialang/original/3X/8/2/82285b419a4a1120841d6293d4fd51bc75a431b1.png)

```julia
Data

7043×2 Matrix{Float64}:
 -1.27735 -1.16024
  0.0663227 -0.259611
 -1.23664 -0.362635
  0.514215 -0.746482
 -1.23664 0.197351
 -0.992332 1.15946
 -0.422287 0.808849
  ⋮          
  1.61359 -1.44937
 -0.340852 0.665945
  1.61359 1.27744
 -0.870179 -1.16855
 -1.1552 0.320315
  1.36928 1.35886
Data= (data .- mean(data,dims=1))./std(data,dims=1)
p

PCA(indim = 7043, outdim = 1, principalratio = 1.0)
p=fit(PCA,Data,maxoutdim=2)
7043×1 Matrix{Float64}:
 -0.0011379038573442269
  0.003166852111996749
 -0.00849202937785105
  0.01224926425921756
 -0.013932997653130772
 -0.020907400623596868
 -0.011962038872230636
  ⋮
  0.029760511490590863
 -0.009782299361486769
  0.003266063598205041
  0.0028990384530702905
 -0.014336507175160657
  0.00010121411503414527
projection(p)
P

7043×1 Matrix{Float64}:
 -0.0011
  0.0032
 -0.0085
  0.0122
 -0.0139
 -0.0209
 -0.012
  ⋮
  0.0298
 -0.0098
  0.0033
  0.0029
 -0.0143
  0.0001
P=round.(projection(p), digits=4)
MethodError: no method matching predict(::Matrix{Float64}, ::Matrix{Float64})

Closest candidates are:

predict(!Matched::MultivariateStats.FactorAnalysis, ::AbstractVecOrMat{T}) where T<:Real at ~/.julia/packages/MultivariateStats/zLpz8/src/fa.jl:64

predict(!Matched::MultivariateStats.ICA, ::AbstractVecOrMat{<:Real}) at ~/.julia/packages/MultivariateStats/zLpz8/src/ica.jl:38

predict(!Matched::MultivariateStats.SubspaceLDA, ::AbstractVecOrMat{T}) where T<:Real at ~/.julia/packages/MultivariateStats/zLpz8/src/lda.jl:427

...

    transform(::Matrix{Float64}, ::Matrix{Float64})@deprecated.jl:72
    top-level scope@Local: 1[inlined]
yte=MultivariateStats.transform(P,data)

```

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<div class="post-metadata">

### Author: ![nalimilan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nalimilan/32/147_2.png) [@nalimilan](https://discourse.julialang.org/u/nalimilan)
#### Post date: [June 16, 2022, 7:12pm UTC](https://discourse.julialang.org/t/multivariatestats-transform-methoderror/82825/2 "2022-06-16T19:12:05Z")

</div>

AFAICT you should call `transform(p, data)` instead (small `p`).

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<div class="post-metadata">

### Author: ![raman\_kumar](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/raman_kumar/32/26782_2.png) [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)
#### Post date: [June 17, 2022, 4:04am UTC](https://discourse.julialang.org/t/multivariatestats-transform-methoderror/82825/3 "2022-06-17T04:04:20Z")

</div>

can you explain me - why i should use small “p” instead of Capital “P” ? Actually MultivariateStats don’t have elaborate documentations.

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<div class="post-metadata">

### Author: ![nalimilan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nalimilan/32/147_2.png) [@nalimilan](https://discourse.julialang.org/u/nalimilan)
#### Post date: [June 17, 2022, 7:23am UTC](https://discourse.julialang.org/t/multivariatestats-transform-methoderror/82825/4 "2022-06-17T07:23:19Z")

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It’s not specific to MultivariateStats, it’s just that you called `p=fit(PCA,Data,maxoutdim=2)` and later `P=round.(projection(p), digits=4)` so the PCA object is stored in `p`, while `P` holds the (rounded) projection matrix.