Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries/ --ompython_omhome=/usr Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.conf.json
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo", uses=false)
Using package ModelicaServices with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo)
Using package Modelica with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo)
Using package Complex with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo)
Running command: translateModel(Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|body1.frame_a.r_0.1.|body1.frame_a.r_0.2.|body1.frame_a.r_0.3.|body1.v_0.1.|body1.v_0.2.|body1.v_0.3.|body1.w_a.1.|body1.w_a.2.|body1.w_a.3.|p2.s|p2.v",fileNamePrefix="Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem")
translateModel(Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|body1.frame_a.r_0.1.|body1.frame_a.r_0.2.|body1.frame_a.r_0.3.|body1.v_0.1.|body1.v_0.2.|body1.v_0.3.|body1.w_a.1.|body1.w_a.2.|body1.w_a.3.|p2.s|p2.v",fileNamePrefix="Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001557/0.001557, allocations: 188.9 kB / 17.27 MB, free: 4.504 MB / 13.93 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.305/1.305, allocations: 222.9 MB / 240.9 MB, free: 10.99 MB / 202.7 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001053/0.001053, allocations: 106.7 kB / 291.2 MB, free: 10.94 MB / 234.7 MB
Notification: Performance of FrontEnd - loaded program: time 0.0008748/0.000875, allocations: 43.94 kB / 350 MB, free: 76 kB / 282.7 MB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.221/0.2218, allocations: 49.44 MB / 399.5 MB, free: 33.37 MB / 298.7 MB
Notification: Performance of NFInst.instantiate(Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem): time 0.03392/0.2558, allocations: 46.96 MB / 446.4 MB, free: 2.23 MB / 314.7 MB
Notification: Performance of NFInst.instExpressions: time 0.0268/0.2827, allocations: 9.954 MB / 456.4 MB, free: 8.242 MB / 330.7 MB
Notification: Performance of NFInst.updateImplicitVariability: time 0.00982/0.2926, allocations: 203.5 kB / 456.6 MB, free: 8.043 MB / 330.7 MB
Notification: Performance of NFTyping.typeComponents: time 0.005459/0.2981, allocations: 2.727 MB / 459.3 MB, free: 5.309 MB / 330.7 MB
Notification: Performance of NFTyping.typeBindings: time 0.004886/0.303, allocations: 1.841 MB / 461.2 MB, free: 3.461 MB / 330.7 MB
Notification: Performance of NFTyping.typeClassSections: time 0.001972/0.305, allocations: 0.7489 MB / 461.9 MB, free: 2.711 MB / 330.7 MB
Notification: Performance of NFFlatten.flatten: time 0.008544/0.3136, allocations: 6.522 MB / 468.4 MB, free: 12.18 MB / 346.7 MB
Notification: Performance of NFFlatten.resolveConnections: time 0.006525/0.3201, allocations: 3.531 MB / 472 MB, free: 8.602 MB / 346.7 MB
Notification: Performance of NFEvalConstants.evaluate: time 0.003537/0.3237, allocations: 1.518 MB / 473.5 MB, free: 7.078 MB / 346.7 MB
Notification: Performance of NFSimplifyModel.simplify: time 0.004325/0.3281, allocations: 2.5 MB / 476 MB, free: 4.57 MB / 346.7 MB
Notification: Performance of NFPackage.collectConstants: time 0.001461/0.3296, allocations: 260 kB / 476.2 MB, free: 4.316 MB / 346.7 MB
Notification: Performance of NFFlatten.collectFunctions: time 0.003433/0.333, allocations: 1.252 MB / 477.5 MB, free: 3.062 MB / 346.7 MB
Notification: Performance of NFScalarize.scalarize: time 0.003296/0.3364, allocations: 2.041 MB / 479.5 MB, free: 1.016 MB / 346.7 MB
Notification: Performance of NFVerifyModel.verify: time 0.005247/0.3416, allocations: 2.345 MB / 481.9 MB, free: 14.66 MB / 362.7 MB
Notification: Performance of NFConvertDAE.convert: time 0.009832/0.3515, allocations: 7.188 MB / 489.1 MB, free: 7.445 MB / 362.7 MB
Notification: Performance of FrontEnd - DAE generated: time 5.631e-06/0.3515, allocations: 4 kB / 489.1 MB, free: 7.441 MB / 362.7 MB
Notification: Performance of FrontEnd: time 1.874e-06/0.3516, allocations: 0 / 489.1 MB, free: 7.441 MB / 362.7 MB
Notification: Performance of Transformations before backend: time 0.0003056/0.3519, allocations: 0 / 489.1 MB, free: 7.441 MB / 362.7 MB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 1686
 * Number of variables: 1686
Notification: Performance of Generate backend data structure: time 0.01326/0.3651, allocations: 5.281 MB / 494.3 MB, free: 2.09 MB / 362.7 MB
Notification: Performance of prepare preOptimizeDAE: time 4.16e-05/0.3652, allocations: 8.031 kB / 494.4 MB, free: 2.082 MB / 362.7 MB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.009049/0.3743, allocations: 2.116 MB / 496.5 MB, free: 15.96 MB / 378.7 MB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.006335/0.3806, allocations: 2.485 MB / 499 MB, free: 13.41 MB / 378.7 MB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.000309/0.381, allocations: 274.9 kB / 499.2 MB, free: 13.14 MB / 378.7 MB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.002135/0.3831, allocations: 435.5 kB / 499.6 MB, free: 12.71 MB / 378.7 MB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.2187/0.6019, allocations: 12.22 MB / 0.4999 GB, free: 95.25 MB / 378.7 MB
Notification: Performance of preOpt findStateOrder (simulation): time 0.0002913/0.6023, allocations: 51.53 kB / 0.4999 GB, free: 95.23 MB / 378.7 MB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.001298/0.6036, allocations: 169.6 kB / 0.5001 GB, free: 95.23 MB / 378.7 MB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 0.004035/0.6076, allocations: 2.166 MB / 0.5022 GB, free: 95 MB / 378.7 MB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.02239/0.63, allocations: 10.21 MB / 0.5122 GB, free: 91.19 MB / 378.7 MB
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.0468/0.6769, allocations: 44.31 MB / 0.5554 GB, free: 46.32 MB / 378.7 MB
Notification: Performance of preOpt comSubExp (simulation): time 0.009728/0.6867, allocations: 4.611 MB / 0.5599 GB, free: 41.52 MB / 378.7 MB
Notification: Performance of preOpt resolveLoops (simulation): time 0.001912/0.6886, allocations: 1.72 MB / 0.5616 GB, free: 39.79 MB / 378.7 MB
Notification: Performance of preOpt evalFunc (simulation): time 0.01084/0.6995, allocations: 8.226 MB / 0.5697 GB, free: 31.24 MB / 378.7 MB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 3.969e-05/0.6996, allocations: 59.81 kB / 0.5697 GB, free: 31.17 MB / 378.7 MB
Notification: Performance of pre-optimization done (n=183): time 5.891e-06/0.6996, allocations: 0 / 0.5697 GB, free: 31.17 MB / 378.7 MB
Notification: Performance of matching and sorting (n=205): time 0.03432/0.7339, allocations: 15.92 MB / 0.5853 GB, free: 15.09 MB / 378.7 MB
Notification: Performance of inlineWhenForInitialization (initialization): time 0.001002/0.735, allocations: 1.601 MB / 0.5868 GB, free: 13.32 MB / 378.7 MB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.005131/0.7401, allocations: 4.195 MB / 0.5909 GB, free: 9.105 MB / 378.7 MB
Notification: Performance of collectPreVariables (initialization): time 0.0005734/0.7407, allocations: 56.12 kB / 0.591 GB, free: 9.047 MB / 378.7 MB
Notification: Performance of collectInitialEqns (initialization): time 0.001713/0.7424, allocations: 3.398 MB / 0.5943 GB, free: 5.602 MB / 378.7 MB
Notification: Performance of collectInitialBindings (initialization): time 0.0008377/0.7433, allocations: 0.8061 MB / 0.5951 GB, free: 4.785 MB / 378.7 MB
Notification: Performance of simplifyInitialFunctions (initialization): time 0.001454/0.7447, allocations: 1.361 MB / 0.5964 GB, free: 3.414 MB / 378.7 MB
Notification: Performance of setup shared object (initialization): time 5.427e-05/0.7448, allocations: 305.2 kB / 0.5967 GB, free: 3.113 MB / 378.7 MB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.002694/0.7475, allocations: 2.262 MB / 0.5989 GB, free: 0.8477 MB / 378.7 MB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.005711/0.7532, allocations: 6.394 MB / 0.6051 GB, free: 8.402 MB / 394.7 MB
Notification: Performance of analyzeInitialSystem (initialization): time 0.01144/0.7647, allocations: 9.326 MB / 0.6143 GB, free: 13.03 MB / 410.7 MB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 0.0001249/0.7649, allocations: 40 kB / 0.6143 GB, free: 12.99 MB / 410.7 MB
Notification: Performance of matching and sorting (n=894) (initialization): time 0.02554/0.7904, allocations: 10.07 MB / 0.6241 GB, free: 2.902 MB / 410.7 MB
Notification: Performance of prepare postOptimizeDAE: time 0.000219/0.7907, allocations: 68 kB / 0.6242 GB, free: 2.836 MB / 410.7 MB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 0.01263/0.8033, allocations: 3.793 MB / 0.6279 GB, free: 15.03 MB / 426.7 MB
Notification: Performance of postOpt tearingSystem (initialization): time 0.01092/0.8143, allocations: 2.16 MB / 0.63 GB, free: 12.86 MB / 426.7 MB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.005636/0.8199, allocations: 1.587 MB / 0.6315 GB, free: 11.27 MB / 426.7 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.009175/0.8292, allocations: 6.072 MB / 0.6375 GB, free: 4.922 MB / 426.7 MB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.006167/0.8354, allocations: 431.4 kB / 0.6379 GB, free: 4.5 MB / 426.7 MB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.001577/0.837, allocations: 412 kB / 0.6383 GB, free: 4.098 MB / 426.7 MB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 665
 * Number of states: 0 ()
 * Number of discrete variables: 45 (damper1.color_b[3],damper1.color_b[2],damper1.color_b[1],damper1.color_a[3],damper1.color_a[2],damper1.color_a[1],spring1.color[3],spring1.color[2],spring1.color[1],spring1.massColor[3],spring1.massColor[2],spring1.massColor[1],spring2.color[3],spring2.color[2],spring2.color[1],spring2.massColor[3],spring2.massColor[2],spring2.massColor[1],p2.boxColor[3],p2.boxColor[2],p2.boxColor[1],body2.sphereColor[3],body2.sphereColor[2],body2.sphereColor[1],bar2.color[3],bar2.color[2],bar2.color[1],bar1.color[3],bar1.color[2],bar1.color[1],body1.sphereColor[3],body1.sphereColor[2],body1.sphereColor[1],world.gravityArrowColor[3],world.gravityArrowColor[2],world.gravityArrowColor[1],world.axisColor_x[3],world.axisColor_x[2],world.axisColor_x[1],world.groundColor[3],world.groundColor[2],world.groundColor[1],world.gravitySphereColor[3],world.gravitySphereColor[2],world.gravitySphereColor[1])
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (856):
 * Single equations (assignments): 847
 * Array equations: 5
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 3
 * Torn equation systems: 1
 * Mixed (continuous/discrete) equation systems: 0
Notification: Equation system details (not torn):
 * Constant Jacobian (size): 0 systems
 * Linear Jacobian (size,density): 2 systems
   {(4,100.0%), (3,100.0%)}
 * Non-linear Jacobian (size): 1 system
   {4}
 * Without analytic Jacobian (size): 0 systems
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 1 system
   {(2,1,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 0 systems
Notification: Performance of prepare postOptimizeDAE: time 0.005628/0.8427, allocations: 2.219 MB / 0.6404 GB, free: 1.867 MB / 426.7 MB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.001051/0.8437, allocations: 375.1 kB / 0.6408 GB, free: 1.496 MB / 426.7 MB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.007811/0.8516, allocations: 3.288 MB / 0.644 GB, free: 14.18 MB / 442.7 MB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 0.005752/0.8574, allocations: 2.742 MB / 0.6467 GB, free: 11.42 MB / 442.7 MB
Notification: Performance of postOpt constantLinearSystem (simulation): time 1.89e-05/0.8574, allocations: 7.984 kB / 0.6467 GB, free: 11.41 MB / 442.7 MB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 3.396e-05/0.8575, allocations: 11.97 kB / 0.6467 GB, free: 11.4 MB / 442.7 MB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.021/0.8785, allocations: 10.35 MB / 0.6568 GB, free: 0.7617 MB / 442.7 MB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 2.933e-05/0.8785, allocations: 24.05 kB / 0.6568 GB, free: 0.7383 MB / 442.7 MB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.001531/0.8801, allocations: 359.5 kB / 0.6572 GB, free: 396 kB / 442.7 MB
Notification: Performance of postOpt tearingSystem (simulation): time 0.003108/0.8832, allocations: 0.9863 MB / 0.6582 GB, free: 15.38 MB / 458.7 MB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 0.0001741/0.8834, allocations: 59.98 kB / 0.6582 GB, free: 15.32 MB / 458.7 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.004844/0.8882, allocations: 4.597 MB / 0.6627 GB, free: 10.46 MB / 458.7 MB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 0.0009901/0.8892, allocations: 1.466 MB / 0.6641 GB, free: 8.852 MB / 458.7 MB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.2718/1.161, allocations: 31.69 MB / 0.6951 GB, free: 149.3 MB / 458.7 MB
Notification: Performance of postOpt removeConstants (simulation): time 0.0007356/1.162, allocations: 438.8 kB / 0.6955 GB, free: 149.2 MB / 458.7 MB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0004187/1.162, allocations: 58.89 kB / 0.6956 GB, free: 149.1 MB / 458.7 MB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.00155/1.164, allocations: 153.5 kB / 0.6957 GB, free: 149.1 MB / 458.7 MB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0002964/1.164, allocations: 176.4 kB / 0.6959 GB, free: 149.1 MB / 458.7 MB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.0001266/1.164, allocations: 70.83 kB / 0.6959 GB, free: 149.1 MB / 458.7 MB
Notification: Performance of sorting global known variables: time 0.003536/1.168, allocations: 2.595 MB / 0.6985 GB, free: 147.8 MB / 458.7 MB
Notification: Performance of sort global known variables: time 3.01e-07/1.168, allocations: 0 / 0.6985 GB, free: 147.8 MB / 458.7 MB
Notification: Performance of remove unused functions: time 0.006613/1.174, allocations: 1.54 MB / 0.7 GB, free: 147.6 MB / 458.7 MB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 60
 * Number of states: 14 ($STATESET1.x[3],$STATESET1.x[2],$STATESET1.x[1],body1.frame_a.r_0[1],body1.frame_a.r_0[2],body1.frame_a.r_0[3],body1.v_0[1],body1.v_0[2],body1.v_0[3],body1.w_a[1],body1.w_a[2],body1.w_a[3],p2.s,p2.v)
 * Number of discrete variables: 0 ()
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for simulation (180):
 * Single equations (assignments): 173
 * Array equations: 3
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 3
 * Torn equation systems: 1
 * Mixed (continuous/discrete) equation systems: 0
Notification: Equation system details (not torn):
 * Constant Jacobian (size): 0 systems
 * Linear Jacobian (size,density): 2 systems
   {(4,100.0%), (3,100.0%)}
 * Non-linear Jacobian (size): 1 system
   {4}
 * Without analytic Jacobian (size): 0 systems
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 1 system
   {(2,1,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 0 systems
Notification: Performance of Backend phase and start with SimCode phase: time 0.0005624/1.175, allocations: 215 kB / 0.7002 GB, free: 147.4 MB / 458.7 MB
Notification: Performance of simCode: created initialization part: time 0.009019/1.184, allocations: 5.979 MB / 0.706 GB, free: 141.5 MB / 458.7 MB
Notification: Performance of simCode: created event and clocks part: time 1.285e-05/1.184, allocations: 7.938 kB / 0.706 GB, free: 141.5 MB / 458.7 MB
Notification: Performance of simCode: created simulation system equations: time 0.003474/1.188, allocations: 2.191 MB / 0.7082 GB, free: 139.2 MB / 458.7 MB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.002961/1.191, allocations: 479.3 kB / 0.7086 GB, free: 138.8 MB / 458.7 MB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.01979/1.21, allocations: 15.32 MB / 0.7236 GB, free: 123.4 MB / 458.7 MB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.004167/1.215, allocations: 3.518 MB / 0.727 GB, free: 119.9 MB / 458.7 MB
Notification: Performance of simCode: alias equations: time 0.004874/1.219, allocations: 2.061 MB / 0.729 GB, free: 117.8 MB / 458.7 MB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0009082/1.22, allocations: 283.4 kB / 0.7293 GB, free: 117.5 MB / 458.7 MB
Notification: Performance of SimCode: time 7.92e-07/1.22, allocations: 3.938 kB / 0.7293 GB, free: 117.5 MB / 458.7 MB
Notification: Performance of Templates: time 0.1122/1.333, allocations: 50.18 MB / 0.7783 GB, free: 67.57 MB / 458.7 MB
make -j1 -f Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.makefile
(rm -f Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.pipe ; mkfifo Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.pipe ; head -c 1048576 < Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.pipe >> ../files/Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.sim & ./Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem  -abortSlowSimulation -alarm=480  -emit_protected -lv LOG_STATS > Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.pipe 2>&1)
diffSimulationResults("Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem_res.mat","/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork@2/Reference-modelica.org/ReferenceResults/MAP-LIB_ReferenceResults/v4.0.0/Modelica/Mechanics/MultiBody/Examples/Elementary/SpringDamperSystem/SpringDamperSystem.csv","../files/Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Elementary.SpringDamperSystem.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches