scipy.optimize.curve_fit raises RuntimeWarning
I am trying to fit a curve by changing two parameters (e and A). The target curve is plotted by assigning n0=0.395, but its actual value is 0.0395. So I am hoping to achieve the same curve by changing e and A.
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
return A*(e+x)**0.0395
strain = np.linspace(0,15,3000) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
However, I constantly get this warning after running the code:
RuntimeWarning: invalid value encountered in power
return A*(e+x)**0.0395
I was wondering why this happens and how should improve the code?
python scipy curve-fitting data-fitting
asked Nov 16 '18 at 0:59
TomTom
8217
add a comment |
I am trying to fit a curve by changing two parameters (e and A). The target curve is plotted by assigning n0=0.395, but its actual value is 0.0395. So I am hoping to achieve the same curve by changing e and A.
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
return A*(e+x)**0.0395
strain = np.linspace(0,15,3000) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
However, I constantly get this warning after running the code:
RuntimeWarning: invalid value encountered in power
return A*(e+x)**0.0395
I was wondering why this happens and how should improve the code?
python scipy curve-fitting data-fitting
asked Nov 16 '18 at 0:59
TomTom
8217
add a comment |
I am trying to fit a curve by changing two parameters (e and A). The target curve is plotted by assigning n0=0.395, but its actual value is 0.0395. So I am hoping to achieve the same curve by changing e and A.
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
return A*(e+x)**0.0395
strain = np.linspace(0,15,3000) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
However, I constantly get this warning after running the code:
RuntimeWarning: invalid value encountered in power
return A*(e+x)**0.0395
I was wondering why this happens and how should improve the code?
python scipy curve-fitting data-fitting
asked Nov 16 '18 at 0:59
TomTom
8217
I am trying to fit a curve by changing two parameters (e and A). The target curve is plotted by assigning n0=0.395, but its actual value is 0.0395. So I am hoping to achieve the same curve by changing e and A.
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
return A*(e+x)**0.0395
strain = np.linspace(0,15,3000) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
However, I constantly get this warning after running the code:
RuntimeWarning: invalid value encountered in power
return A*(e+x)**0.0395
I was wondering why this happens and how should improve the code?
python scipy curve-fitting data-fitting
python scipy curve-fitting data-fitting
asked Nov 16 '18 at 0:59
TomTom
8217
asked Nov 16 '18 at 0:59
TomTom
8217
asked Nov 16 '18 at 0:59
TomTom
8217
asked Nov 16 '18 at 0:59
TomTom
8217
asked Nov 16 '18 at 0:59
TomTom
8217
8217
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
I found a solution that I do not like, but it does eliminate the warning. I found that, strangely to me, "e" was being made negative within curve_fit(). I added a "brick wall" inside the function to stop this, but it should be unnecessary. My code is:
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
if e < 0.0: # curve_fit() hits a "brick wall" if e is negative
return 1.0E10 # large value gives large error, the "brick wall"
return A*(e+x)**0.0395
strain = np.linspace(0,0.1,3) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53329980%2fscipy-optimize-curve-fit-raises-runtimewarning%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
I found a solution that I do not like, but it does eliminate the warning. I found that, strangely to me, "e" was being made negative within curve_fit(). I added a "brick wall" inside the function to stop this, but it should be unnecessary. My code is:
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
if e < 0.0: # curve_fit() hits a "brick wall" if e is negative
return 1.0E10 # large value gives large error, the "brick wall"
return A*(e+x)**0.0395
strain = np.linspace(0,0.1,3) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
add a comment |
I found a solution that I do not like, but it does eliminate the warning. I found that, strangely to me, "e" was being made negative within curve_fit(). I added a "brick wall" inside the function to stop this, but it should be unnecessary. My code is:
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
if e < 0.0: # curve_fit() hits a "brick wall" if e is negative
return 1.0E10 # large value gives large error, the "brick wall"
return A*(e+x)**0.0395
strain = np.linspace(0,0.1,3) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
add a comment |
I found a solution that I do not like, but it does eliminate the warning. I found that, strangely to me, "e" was being made negative within curve_fit(). I added a "brick wall" inside the function to stop this, but it should be unnecessary. My code is:
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
if e < 0.0: # curve_fit() hits a "brick wall" if e is negative
return 1.0E10 # large value gives large error, the "brick wall"
return A*(e+x)**0.0395
strain = np.linspace(0,0.1,3) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
I found a solution that I do not like, but it does eliminate the warning. I found that, strangely to me, "e" was being made negative within curve_fit(). I added a "brick wall" inside the function to stop this, but it should be unnecessary. My code is:
import numpy as np
from scipy.optimize import curve_fit
def func(x,e,A):
if e < 0.0: # curve_fit() hits a "brick wall" if e is negative
return 1.0E10 # large value gives large error, the "brick wall"
return A*(e+x)**0.0395
strain = np.linspace(0,0.1,3) # variable
e = 0.773
A = 386.5
n0 = 0.395
y = A*(e+strain)**n0 # target to minimize
popt, pcov = curve_fit(func, strain, y)
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
answered Nov 16 '18 at 2:50
James PhillipsJames Phillips
1,775388
1,775388
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53329980%2fscipy-optimize-curve-fit-raises-runtimewarning%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
