NCV must be greater than NEV and less than or equal to N.

[Gholamreza]

Hello Opensees community,
when I do SDOF analysis with Zerolength element I get this error:
NCV must be greater than NEV and less than or equal to N.

...................................................................................................................
below is my code. Can anyone tell where I made a mistake(s).

...................................................................................................................

wipe all;
model BasicBuilder -ndm 2 -ndf 3;


# define nodal coordinates:
node 1 0. 0. 0.;
node 2 0. 0. 0.;

# Single point constraints -- Boundary Conditions
fix 1 1 1 1;
fix 2 0 1 1;

# mass
set g 9.81; #m/sec2
set m 1000.;

# assign mass
mass 2 $m 0. 0.;

# Define Elastic Material
uniaxialMaterial Elastic 1 7840.

# Define Elements
element zeroLength 1 1 2 -mat 1 -dir 1

puts "Model Built"

#timeSeries Path $tag -dt $dt -filePath $filePath <-factor $cFactor>
timeSeries Path 1 -dt 0.01 -filePath TAKY.th -factor [expr 0.30*$g];

# Define RECORDERS -------------------------------------------------------------
recorder Node -file $Output/Disp.out -time -node 2 -dof 1 disp;

#first eigen
set freq [expr [eigen 1]**0.5]
set period [expr 2*$pi/$freq]
puts $period

#pattern UniformExcitation $patternTag $dir -accel $tsTag <-vel0 $ver0>
pattern UniformExcitation 1 1 -accel 1;


# create the analysis
wipeAnalysis;
constraints Transformation;
numberer RCM;
system UmfPack;
test EnergyIncr 1.0e-10 100;
algorithm KrylovNewton;
integrator Newmark 0.5 0.25 ;
analysis Transient;
analyze [expr 10*4096] 0.001;

puts "Done!"

...................................................................................................................
Thanks.

[selimgunay]

It works if you use [eigen -fullGenLapack 1]

[Gholamreza]

Thanks selimgunay,
It worked indeed.
Can you tell me what that is ?

[selimgunay]

The standard eigen command requires at least n+1 degrees of freedom with mass, where n is the number of the eigenvalues in the eigen command. The fullGenLapack algorithm does not have such restriction. You also need the mass proportional rayleigh damping, otherwise your damping is zero.

[Gholamreza]

I got it. Thank you so much.