问题描述
问题已更新
以前,我模型中的控制变量m.P范围很广,导致求解器失败。根据约翰博士的建议,我在目标函数中尝试了 logarithmic scaling of P。 虽然新错误出现错误代码“位置 4”:
*** Error in syntax of function string: Missing opening parenthesis
Position: 4
log_p-(log10(p))
?
以下是模型和求解器设置的一部分。 模型中,我有控制变量m.log_P,两个多变量m.u_1、m.u_2,其他变量P、Q、D_1、D_2为状态变量,小写字母均为常量。)>
m.log_P = m.CV(value = np.log10(P_ini),name = 'log_P') # log_P for scaling
m.log_P.STATUS = 1 # add log_P to objective function,instead of P
m.log_P.FSTATUS = 1
m.P= m.SV(value = P_ini,name = 'P') # now original P is treated as a state variable
m.u_1 = m.MV(value=u_0,lb = 0,name = 'u_1')
m.u_2 = m.MV(value=u_0,name = 'u_2')
m.u_1.STATUS = 1
m.u_1.FSTATUS = 1
m.u_2.STATUS = 1
m.u_2.FSTATUS = 1
m.Equations([m.P.dt() == (a-mm-n) * m.P + b * m.Q - k_1 * m.D_1 * m.P - k_2 * m.D_2 * m.P,m.Q.dt() == mm*m.P - b*m.Q,m.D_1.dt() == m.u_1 - r_1 * m.D_1,m.D_2.dt() == m.u_2 - r_2 * m.D_2,m.log_P == m.log10(m.P)]) # first 4 equations defined by model. The last equation take logrithmic value of P.
m.options.IMODE = 6
m.options.SOLVER = 3
m.options.CV_TYPE = 2 # l2-norm
m.options.EV_TYPE = 2
m.solver_options = ['linear_solver mumps',\
'mu_strategy adaptive']
这里我用 '''m.options.CV_TYPE = 2 # l2-norm''' 设置了二次误差项。
for i in range(len(t)-1):
ts = [t[i],t[i+1]]
y = odeint(chemo_model,x0,ts,args = (u_infu1[i],u_infu2[i])) # 'chemo_model' is a model function
P_cell[i+1] = y[-1][0]
Q_cell[i+1] = y[-1][1]
D1_drug[i+1] = y[-1][2]
D2_drug[i+1] = y[-1][3]
''' update '''
m.log_P.MEAS = np.log10(P_cell[i+1]) # insert measurement
m.log_P.SP = np.log10(P_sp[i+1]) # P_sp is predefined trajectory points
''' solve MPC '''
m.solve(disp=True)
一个带有 error code 'Position 5' 的在线案例是由于该等式中缺少“dt()”。看起来很相似,但不是我的情况。谁可以帮我这个事?提前致谢!!
解决方法
通过不使用保留关键字来命名变量来解决此错误。
name = 'log_P'
变量名如 lg_P
会起作用。以下是 reserved keywords in APMonitor 的列表:
abs() Absolute value abs(x*y)=0
exp() Exponentiation exp(x*y)=0
log10() Base-10 Log log10(x*y)=0
log() Natural Log log(x*y)=0
sqrt() Square Root sqrt(x*y)=0
sinh() Hyperbolic Sine sinh(x*y)=0
cosh() Hyperbolic Cosine cosh(x*y)=0
tanh() Hyperbolic Tangent tanh(x*y)=0
sin() Sine sin(x*y)=0
cos() Cosine cos(x*y)=0
tan() Tangent tan(x*y)=0
asin() Arc-sine asin(x*y)=0
acos() Arc-cos acos(x*y)=0
atan() Arc-tangent atan(x*y)=0
erf() Error function erf(x*y)=0
erfc() Complementary error function erfc(x*y)=0