Error in sliding semilandmarks

[Pablo Fisichella]

Dear Geomorph Team,

I am using 45 landmarks and semilandmarks (landmarks 1 and 45 fixed and 2-44 semilandmarks) to investigate bone curvature in 25 specimens.

I wrote the following simple script:

library(geomorph).

data<-read.csv("Semi-Landmarks.csv", sep=";", header=FALSE)

coords<-as.matrix(datos[, -1]) storage.mode(coords)<-'numeric'

landmarks<-geomorph::arrayspecs(coords,p=45,k=3)

curve.mat<-geomorph::define.sliders(curves=list(2:24,26:44),nLandmarks=45)

gpagen(landmarks, curves = curve.mat, PrinAxes = FALSE)

However, I always get this error:

Error in geomorph::define.sliders(curves = list(2:24, 26:44), nLandmarks = 45): arguments were not used (curves = list(2:24, 26:44), nLandmarks = 45).

I've tried several solutions, including updating the geomorph version, but the error persists (I'm using version 4.0.10).

Can someone tell me where the error is?

I've attached my dataset in case it's needed.

Thank you in advance for any help with this basic question.

All the best,

Paolo

[Adams, Dean [EEOB]]

Paolo,

There are several errors in your script.

1: you read in 'data' but later call 'datos' (easy fix)

2: you have multiple lines of code together (easy fix)

3: your use of 'define.sliders' is not correct. This last one is where the error is thrown, as your usage is not proper. 

For instance, there is no 'nLandmarks' argument in the function. There is an argument 'nsliders'. There also is not 'curves' argument; but there is a 'landmarks' argument. Please see the help file for the function for proper usage.

Fixing those errors (with some assumptions of what you intended), I can the function to run: 

curve.mat<-geomorph::define.sliders(landmarks=c(2:24,26:44),nsliders = 45)
curve.mat

However, since I do not know which of your points are intended to be sliders on the curve I cannot tell whether this is correct or what you intend for your data. 

Dean

-- 
Dr. Dean C. Adams
Distinguished Professor
Director, Ecology and Evolutionary Biology Graduate Program
Department of Ecology, Evolution, and Organismal Biology
Iowa State University
www.public.iastate.edu/~dcadams/
phone: 515-294-3834

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From: geomorph-...@googlegroups.com <geomorph-...@googlegroups.com> on behalf of Pablo Fisichella <fisiche...@gmail.com>
Sent: Friday, January 16, 2026 8:41 AM
To: geomorph R package <geomorph-...@googlegroups.com>
Subject: [geomorph-r-package] Error in sliding semilandmarks

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