{
  "__type": "IngestedDoc",
  "__tag": 4010,
  "_content": {
    "Notes": {
      "__type": "Section",
      "__tag": 4015,
      "children": [
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "The argument "
            },
            {
              "__type": "InlineCode",
              "__tag": 4051,
              "value": "function"
            },
            {
              "__type": "Text",
              "__tag": 4046,
              "value": " can be one of:"
            }
          ]
        },
        {
          "__type": "BulletList",
          "__tag": 4053,
          "ordered": false,
          "start": 1,
          "children": [
            {
              "__type": "ListItem",
              "__tag": 4054,
              "children": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "PyCapsule, whose name contains the C function signature"
                    }
                  ]
                }
              ]
            },
            {
              "__type": "ListItem",
              "__tag": 4054,
              "children": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "ctypes function pointer"
                    }
                  ]
                }
              ]
            },
            {
              "__type": "ListItem",
              "__tag": 4054,
              "children": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "cffi function pointer"
                    }
                  ]
                }
              ]
            }
          ]
        },
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "The signature of the low-level callback must match one of those expected by the routine it is passed to."
            }
          ]
        },
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "If constructing low-level functions from a PyCapsule, the name of the capsule must be the corresponding signature, in the format      "
            }
          ]
        },
        {
          "__type": "Code",
          "__tag": 4050,
          "value": "return_type (arg1_type, arg2_type, ...)",
          "execution_status": null
        },
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "For example      "
            }
          ]
        },
        {
          "__type": "Code",
          "__tag": 4050,
          "value": "\"void (double)\"\n\"double (double, int *, void *)\"",
          "execution_status": null
        },
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "The context of a PyCapsule passed in as "
            },
            {
              "__type": "InlineCode",
              "__tag": 4051,
              "value": "function"
            },
            {
              "__type": "Text",
              "__tag": 4046,
              "value": " is used as "
            },
            {
              "__type": "InlineCode",
              "__tag": 4051,
              "value": "user_data"
            },
            {
              "__type": "Text",
              "__tag": 4046,
              "value": ", if an explicit value for "
            },
            {
              "__type": "InlineCode",
              "__tag": 4051,
              "value": "user_data"
            },
            {
              "__type": "Text",
              "__tag": 4046,
              "value": " was not given."
            }
          ]
        }
      ],
      "title": [],
      "level": 0,
      "target": null
    },
    "Warns": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    },
    "Raises": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    },
    "Yields": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    },
    "Methods": {
      "__type": "Section",
      "__tag": 4015,
      "children": [
        {
          "__type": "Parameters",
          "__tag": 4026,
          "children": [
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "from_cython",
              "annotation": "",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "Class method for constructing callables from Cython C-exported functions."
                    }
                  ]
                }
              ]
            }
          ]
        }
      ],
      "title": [],
      "level": 0,
      "target": null
    },
    "Returns": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    },
    "Summary": {
      "__type": "Section",
      "__tag": 4015,
      "children": [
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "Low-level callback function."
            }
          ]
        }
      ],
      "title": [],
      "level": 0,
      "target": null
    },
    "Receives": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    },
    "Warnings": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    },
    "Attributes": {
      "__type": "Section",
      "__tag": 4015,
      "children": [
        {
          "__type": "Parameters",
          "__tag": 4026,
          "children": [
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "function",
              "annotation": "",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "Callback function given."
                    }
                  ]
                }
              ]
            },
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "user_data",
              "annotation": "",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "User data given."
                    }
                  ]
                }
              ]
            },
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "signature",
              "annotation": "",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "Signature of the function."
                    }
                  ]
                }
              ]
            }
          ]
        }
      ],
      "title": [],
      "level": 0,
      "target": null
    },
    "Parameters": {
      "__type": "Section",
      "__tag": 4015,
      "children": [
        {
          "__type": "Parameters",
          "__tag": 4026,
          "children": [
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "function",
              "annotation": "{PyCapsule, ctypes function pointer, cffi function pointer}",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "Low-level callback function."
                    }
                  ]
                }
              ]
            },
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "user_data",
              "annotation": "{PyCapsule, ctypes void pointer, cffi void pointer}",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "User data to pass on to the callback function."
                    }
                  ]
                }
              ]
            },
            {
              "__type": "DocParam",
              "__tag": 4016,
              "name": "signature",
              "annotation": "str, optional",
              "desc": [
                {
                  "__type": "Paragraph",
                  "__tag": 4045,
                  "children": [
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": "Signature of the function. If omitted, determined from "
                    },
                    {
                      "__type": "Emphasis",
                      "__tag": 4047,
                      "children": [
                        {
                          "__type": "Text",
                          "__tag": 4046,
                          "value": "function"
                        }
                      ]
                    },
                    {
                      "__type": "Text",
                      "__tag": 4046,
                      "value": ", if possible."
                    }
                  ]
                }
              ]
            }
          ]
        }
      ],
      "title": [],
      "level": 0,
      "target": null
    },
    "Extended Summary": {
      "__type": "Section",
      "__tag": 4015,
      "children": [
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "Some functions in SciPy take as arguments callback functions, which can either be python callables or low-level compiled functions. Using compiled callback functions can improve performance somewhat by avoiding wrapping data in Python objects."
            }
          ]
        },
        {
          "__type": "Paragraph",
          "__tag": 4045,
          "children": [
            {
              "__type": "Text",
              "__tag": 4046,
              "value": "Such low-level functions in SciPy are wrapped in "
            },
            {
              "__type": "CrossRef",
              "__tag": 4002,
              "value": "LowLevelCallable",
              "reference": {
                "__type": "LocalRef",
                "__tag": 4022,
                "kind": "module",
                "path": "scipy._lib._ccallback:LowLevelCallable"
              },
              "kind": "module"
            },
            {
              "__type": "Text",
              "__tag": 4046,
              "value": " objects, which can be constructed from function pointers obtained from ctypes, cffi, Cython, or contained in Python "
            },
            {
              "__type": "InlineRole",
              "__tag": 4003,
              "value": "PyCapsule",
              "domain": null,
              "role": null,
              "inventory": null
            },
            {
              "__type": "Text",
              "__tag": 4046,
              "value": " objects."
            }
          ]
        },
        {
          "__type": "Admonition",
          "__tag": 4056,
          "kind": "seealso",
          "base_type": "note",
          "children": [
            {
              "__type": "AdmonitionTitle",
              "__tag": 4055,
              "children": [
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": "seealso "
                }
              ]
            },
            {
              "__type": "Paragraph",
              "__tag": 4045,
              "children": [
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": "Functions accepting low-level callables:"
                }
              ]
            },
            {
              "__type": "Paragraph",
              "__tag": 4045,
              "children": [
                {
                  "__type": "CrossRef",
                  "__tag": 4002,
                  "value": "scipy.integrate.quad",
                  "reference": {
                    "__type": "LocalRef",
                    "__tag": 4022,
                    "kind": "module",
                    "path": "scipy.integrate.quadpack"
                  },
                  "kind": "module"
                },
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": ", "
                },
                {
                  "__type": "CrossRef",
                  "__tag": 4002,
                  "value": "scipy.ndimage.generic_filter",
                  "reference": {
                    "__type": "RefInfo",
                    "__tag": 4000,
                    "module": "scipy",
                    "version": "*",
                    "kind": "api",
                    "path": "scipy.ndimage._filters:generic_filter"
                  },
                  "kind": "module"
                },
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": ", "
                },
                {
                  "__type": "CrossRef",
                  "__tag": 4002,
                  "value": "scipy.ndimage.generic_filter1d",
                  "reference": {
                    "__type": "RefInfo",
                    "__tag": 4000,
                    "module": "scipy",
                    "version": "*",
                    "kind": "api",
                    "path": "scipy.ndimage._filters:generic_filter1d"
                  },
                  "kind": "module"
                },
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": ", "
                },
                {
                  "__type": "CrossRef",
                  "__tag": 4002,
                  "value": "scipy.ndimage.geometric_transform",
                  "reference": {
                    "__type": "RefInfo",
                    "__tag": 4000,
                    "module": "scipy",
                    "version": "*",
                    "kind": "api",
                    "path": "scipy.ndimage._interpolation:geometric_transform"
                  },
                  "kind": "module"
                }
              ]
            },
            {
              "__type": "Paragraph",
              "__tag": 4045,
              "children": [
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": "Usage examples:"
                }
              ]
            },
            {
              "__type": "Paragraph",
              "__tag": 4045,
              "children": [
                {
                  "__type": "InlineRole",
                  "__tag": 4003,
                  "value": "ndimage-ccallbacks",
                  "domain": null,
                  "role": "ref",
                  "inventory": null
                },
                {
                  "__type": "Text",
                  "__tag": 4046,
                  "value": ", "
                },
                {
                  "__type": "InlineRole",
                  "__tag": 4003,
                  "value": "quad-callbacks",
                  "domain": null,
                  "role": "ref",
                  "inventory": null
                }
              ]
            }
          ]
        }
      ],
      "title": [],
      "level": 0,
      "target": null
    },
    "Other Parameters": {
      "__type": "Section",
      "__tag": 4015,
      "children": [],
      "title": [],
      "level": 0,
      "target": null
    }
  },
  "_ordered_sections": [
    "Summary",
    "Extended Summary",
    "Parameters",
    "Attributes",
    "Methods",
    "Returns",
    "Yields",
    "Receives",
    "Other Parameters",
    "Raises",
    "Warns",
    "Warnings",
    "Notes"
  ],
  "item_file": "/scipy/_lib/_ccallback.py",
  "item_line": 26,
  "item_type": "class",
  "aliases": [
    "scipy.LowLevelCallable"
  ],
  "example_section_data": {
    "__type": "Section",
    "__tag": 4015,
    "children": [],
    "title": [],
    "level": 0,
    "target": null
  },
  "see_also": [],
  "signature": {
    "__type": "SignatureNode",
    "__tag": 4029,
    "kind": "function",
    "parameters": [
      {
        "__type": "SigParam",
        "__tag": 4030,
        "name": "function",
        "annotation": {
          "__type": "Empty",
          "__tag": 4031
        },
        "kind": "POSITIONAL_OR_KEYWORD",
        "default": {
          "__type": "Empty",
          "__tag": 4031
        }
      },
      {
        "__type": "SigParam",
        "__tag": 4030,
        "name": "user_data",
        "annotation": {
          "__type": "Empty",
          "__tag": 4031
        },
        "kind": "POSITIONAL_OR_KEYWORD",
        "default": "None"
      },
      {
        "__type": "SigParam",
        "__tag": 4030,
        "name": "signature",
        "annotation": {
          "__type": "Empty",
          "__tag": 4031
        },
        "kind": "POSITIONAL_OR_KEYWORD",
        "default": "None"
      }
    ],
    "return_annotation": {
      "__type": "Empty",
      "__tag": 4031
    },
    "target_name": "LowLevelCallable"
  },
  "references": null,
  "qa": "scipy._lib._ccallback:LowLevelCallable",
  "arbitrary": [],
  "local_refs": [
    "from_cython",
    "function",
    "signature",
    "user_data"
  ]
}